AT-1 (625) Constructor was the object of repression. Works with AT-1 SP-gun was over after that. A few vehicles had produced.
Remove it.
Russian
Machine translation
SU-5-1 (645), SU-5-3 (647) were experimental.
Remove it.
SU-5-2 (646) has 10 shells in vehicle (25 in game). There are good pictures of this SP-gun (wrong picture in the game), follow the link:
Russian
Machine translation
SU-1-12 (623): has 36 shells in vehicle (30 in game).
Russian
Machine translation