Something to try once you’ve created a correctly named folder (they can be case sensitive so make sure upper and lower case letters are in the correct places) and sub-folders in the correct place, and the sights still don’t show up in the reticle options in-game, is to run a file integrity check as well so that the game goes through all the files and makes sure they are there and working correctly.
If there are still issues then i would create a bug report. You can bug report it here (just search a bit first so that you don’t report something that is already reported and known about): (Gaijin.net // Issues)
A guide on how to report bugs can be found here: ([Navigation] Technical Knowledge Base | War Thunder Wiki)