The CZ52, if I recall correctly, was originally built to use 9mm Para and the Czechs ended up using the 7.62mm Tokarev because of Soviet "encouragement." If your serial numbers match and its an original 9mm Para barrel (not a later made drop-in barrel) you have a real cool find. I think replacing rollers is really a judgment call. I have not replaced the rollers in my CZ52 and its going strong firing the "hotter" 7.62 Tokarev ammo. You really need to post some images!