I would have loved to help but I’d say I’d be grasping at straws, I’d even go as far as trying to mail Renault with a request to send the sekrit documents on the vehicle since I see no other way to get them for vehicles this obscure.
its more complicated than just affiliations with Renault. French archives are at Vincennes and Chatellerault, the photo of UE 57 and the copy of Galliot muzzlebrake is in British Shrivenham
I just asked Tank Encyclopedia guys to check if it’s really MG151/20 - it looked too tiny for Fouga when I looked at AMX 70.
They said it’s one of Hispano-Suizas, one being HS404.
If it’s really one it actually has not 27mm, but 38mm of penetration as already in-game (e.g. D.520 plane)