Hmm, why can't you do the ZSU-23-4M then? I have little knowledge of the different ZSU-23-4 SPAAG models, but from what I can infer, the M seems to be better than the V1. Just observing. And also, do you need actual time in the cockpit of a SAM system to make it "realistic to the switch", or can you just have access to the system's manual? I ask because I have access to the manual of the SA-13 and SA-19. Where did I get them from, funny thing, the steelbeasts website!