Here’s a, at least almost, complete list of all of the vehicles built from 1919 to 1940, plus some others. It does include vehicle that were otherwise unarmed in some fashion, though still had mounts for the weaponry. It doesn’t include any production variations that might’ve happened during the course their productions aside from major ones:
Scout Cars (Car, Scout); subdivision of armored cars specialized in reconnaissance, first introduced in 1929~
Spoiler
- T7: 1934, 3 prototypes built
- M1: Standardized 1935, 76 built plus 3 T7 prototypes
- M2A1/M3: 1939, 60~ built
- M3A1: 1939-1944, 17,000~ built
- 1940: trialed with 103 hp DJXD diesel engine
- 1940: trialed with 81 hp 6DT-317 diesel engine, later produced as the exported M3A1E1
- M3A1 Command: 1940s, unknown numbers converted
- M3A1E3: 1940s, 1 prototype built
Armored Cars (Car, Armored); armored and wheel vehicles meant to serve in a multitude of roles, ranging from direct combat support to reconnaissance
Spoiler
- T7: 1929, 6 prototypes built
- T4: 1931, 2 prototypes built
- M1: Standardized 1931, 10 built plus 2 T4 prototypes
- T11: 1932, 1 prototype built was unarmed
- T11E1: 1934, 5 prototypes built was unarmed
- T11E2: 1936, 1 prototype built was unarmed
- TH-310: 1934, export for Iran but trialed (and rejected) by the United States
- TK-5: 1934, TH-310 export to Iran, locally modified
- TK-6: 1933, export to Iran but trialed (and rejected) by the United States
- Tucker Tiger: 1938, 1 prototype built had mockup weaponry
Convertible Combat Cars (Car, Combat, Convertible): tanks for the cavalry branch that utilized the Christie suspension
Spoiler
- T1: 1932, 4 prototypes built
- 1933: radio installed
- T1E1: 1932, 1 converted T1E1
- T1E3: 1932, 1 converted T1E1
- T2: 1931, 1 prototype built
- T2E1: 1932, 1 prototype built
- T4: 1933, 1 prototype built was unarmed
- T4E1: 1934, 1 converted T4
- T4E2: 1935, 1 converted T4E1
- T7: 1 prototype built
Combat Cars (Car, Combat): tanks for the cavalry branch, redesignated light tanks in 1940
Spoiler
- T5E1: 1935, 1 prototype built
- T5E2: 1935, 1 prototype built
- M1: Standardized 1936-1937, 89 built plus 1 T5E2 prototype
- 1936: D-shaped turret replaced by irregular octagonal turret
- 1940: redesignated to the Tank, Light, M1A1
- M1E2: 1937, 1 converted M1, later reverted was unarmed
- M1A1: 1938, 17 built
- 1940: redesignated to the Tank, Light, M1A1
- M1E3: 1938, 1 prototype built was unarmed
- M2: 1940, 34 built
- 1940: redesignated to the Tank, Light, M1A2
- M1E1: 1936, 3 built
- 1940: redesignated to the Tank, Light, M1A1
- M1A1E1: 1938, 7 built
- 1940: redesignated to the Tank, Light, M1A1
- M2 Diesel: 1940, portion of the 34 M2 built
- 1940: redesignated to the Tank, Light, M1A2
Light Tanks (Tank, Light); tanks for the infantry branch within the “light” (13> t) weight range, combat cars redesignated light tanks in 1940
Spoiler
- M1917A1: 1929-1930, 8 converted M1917
- T1: 1927, 1 prototype built
- T1E1: 1928, 4 prototypes built
- Later 1928: briefly standardized as the Tank, Light, M1, reverted the same year
- T1E2: 1929, 1 prototype built
- 1930: rearmed with a 37-mm M1916
- T1E3: 1930, 1 converted T1E1
- T1E4: 1932, 1 converted T1E1
- Later 1932: reengined with a 140 hp Cunningham V8
- T1E6, 1932, 1 converted T1E4
- T1E5: 1932, 1 converted T1E1
- T2: 1934, 1 prototype built
- T2E1: 1934, 1 converted T2
- M2A1: Standardized 1935, 9 built
- 1939: synchromesh transmission installed
- T2E2: 1935, 1 prototype built
- M2A2: Standardized 1935-1937, 238 built plus 1 T2E2 prototype already in-game
- 1936: curved turrets replaced by angled-face turrets
- 1939: synchromesh transmission installed
- M2A2E2: 1937, 1 converted M2A2 was unarmed
- M2A2E3: 1938, 1 converted M2A2E3 was unarmed
- M2A3: 1938, 73 built
- 1939: synchromesh transmission installed
- M2A3E2: 1940~, 1 converted M2A3 was unarmed(?)
- M2A3E3: 1941, 1 converted M2A3 was unarmed
- M2A4 prototype: 1939, 1 converted M2A3
- Later 1939: cupola and additional sponson machine gun installed, 37-mm M3 shortened to a 37-mm M5
- M2A4: 1939-1942, 374 built plus 1 prototype already in-game
- M2A2E1: 1937, 3 built
- 1939: synchromesh transmission installed
- M2A3E1: 1938, 8 built
- 1939: synchromesh transmission installed
- M2A4 Diesel: portion of the 374 M2A4 built
- CTL-3 prototype: 1936, 1 prototype built
- CTM-3B: 1943, 5 built
- CTMS-1TB1: 1943, export to the Netherlands but trialed (and rejected) by the United States
- MTLS-1G14: 1943, export to the Netherlands but trialed (and rejected) by the United States
Convertible Medium Tanks (Tank, Medium, Convertible): tanks for the infantry branch within the “medium” weight range that utilized the Christie suspension, though all tanks were within the “light” (13> t) weight range
Spoiler
- M1919 Convertible: 1921, 1 prototype built had mockup weaponry(?)
- M1921 Convertible: 1922, 1 prototype built had mockup weaponry(?)
- M1931 Convertible: 1931, 1 prototype built
- T3: 1932, 2 prototypes built
- Later 1932: driver’s windshield installed
- 1933: driver’s windshield removed, radio installed
- T3E1: 1932, 1 prototype built
- Later 1932: floor reinforced
- Even later 1932: driver’s windshield installed
- 1933: driver’s windshield removed, radio installed
- T3E2: 1933, 5 prototypes built
- T3E3: 1934, 5 converted T3E2
- T4: 1935-1936, 16 prototypes built
- 1940: standardized as the Tank, Medium, Convertible M1
- T4E1: 1935, 3 prototypes built
Medium Tanks (Tank, Medium): tanks for the infantry branch within the “medium” (13< t) weight range
Spoiler
- M1921: 1921, 1 prototype built
- 1922: reengined with a 338 hp Liberty L-12
- 1925: reengined with a 200 hp Packard
- M1922: 1922, 1 prototype built
- Later 1922: cables replaced by chains in suspension
- T1: 1927, 1 prototype built
- 1928: briefly standardized as the Tank, Medium, M1, reverted the same year
- 1931: rearmed with a 75-mm M1920
- T1E1: 1932, 1 converted T1
- T2: 1930, 1 prototype built
- 1931: hull rearmed with a T1 gun system
- 1932: hull rearmed with a cal. .30 M1919, anti-aircraft machine gun mount added was unarmed aside from the hull cal. .30 M1919
- T5 Phase I: 1938, 1 prototype built
- T5E1: 1938, 1 converted T5 Phase I
- T5 Phase III: 1939, 1 prototype built
- M2: Standardized 1939, 18 built
- Later 1939: M19 gun mount installed already in-game
- M2A1: 1940-1941, 94 vehicles
- 1941: M21 gun mount installed
- 1940s: 3-inch (76.2 mm) applique developed
- T5E2: 1939, 1 prototype built
Heavy Tanks (Tank, Heavy): tanks for the infantry branch within the “heavy” (30+ t) weight range
Spoiler
- Mark VIII pilot: 1919, 1 prototype
- Mark VIII: 1920, 99 built plus 1 Mark VIII prototype
- 1925: strobe cupola installed on one Mark VIII, removed the same year
- 1932: air-cooled engine installed on one Mark VIII
Howitzer/Gun Motor Carriages (Carriage, Motor, [DIAMETER]-mm Howitzer/Gun): self-propelled and self-contained guns, utilized as indirect or direct, or both, firepower
Spoiler
- T1: 1930, 1 prototype built
- M2A1 AT: 1937, 1 converted M2A1
- T3: 1940, 1 prototype built
It should be noted that possible additions should be taken very liberally in this list. As already stated, some were unarmed albeit still had the turrets and mounts for the guns. This was done to some prototypes, such as the T11 armored cars and the 1932 version of the T2 medium, since it wasn’t considered to be necessary, whereas others never had them installed, albeit the holes for their installation were still there, because they were focused on testing mobility, such as the T2 light tanks and the experimental M1 combat cars and M2 light tanks.
In other cases, the performance of the gun is in question. I am not certain that the 37-mm M1916, utilized by a bulk of Christie’s tanks, would be usable in-game since it only has a base-fuzed high-explosive shell available to it for armor-piercing purposes. This was considered suitable during the 1920s and I guessed estimated that it would have somewhere between 20 mm to 25 mm of penetration based on the performance of the M63 in-game. However, if it’s lower, then it could very well be unusable. The only saving possibility is that they’re given the mle 1927 and 1936 APCR that the French developed for their S.A. mle 18 guns.
Another one of these cases are those of the T2 and T3 Brownings utilized by part of the T1 lights and as a hull gun on the T2 medium. I have no idea what their performance is and no one else seems to know either. They were considered suitable for anti-tank purposes – but, given that was in comparison to the 37-mm M1916, that isn’t very reassuring. The only hint to their performance is that the T2 fired a 37x123B cartridge at 2,000 fps and that the T3 fired a 37x120R cartridge at 1,350 fps.
Lastly – the 75-mm guns from this era had no armor-piercing capability. This was considered to be okay, since the concussive force alone was enough to crack the 0.6-inch armor of the M1917 light tank when the T1 medium tank tested its 75-mm M1920 against it. This, of course, wouldn’t be possible in-game since concussive force and armor degradation isn’t modeled. This was the same case for the 75-mm guns utilized by the T1 and the T3, though they had no intention to serve as anti-tank guns in those cases. They could be given the high-explosive anti-tank projectiles that were later introduced into their cartridges, but, at least in the case of the T1 medium, it would be quite weird to see.
Edit: Added the Mark VIII since it is, by a technicality, an interwar tank. The United States didn’t receive their first Mark VIII pilot vehicle until 1919, which was then refined into the American version of the Mark VIII which went into production the following year. It also had two modifications during its service, though they wouldn’t have a real difference between one another (aside from the pilot vehicle) if they were all added to the game.