indeed the PSZH-IV is alos a FUG
.Furthermore there are some more versions than the APC and Scout Car (this two are different vehicles in my opinion and I know about some literature where they have seperate entries).
Ref. the East German Borderguard question. I have to say that I am not 100% sure as I am not too interested in that but from what I read, the PSZH-IV was in use with the East German Border Guards (Grenztruppen) as well as with the "Wachregiment Feliks Dzierzynski" of the MfS.
Best regards,
Ben