I have one complete, NOS first generation gas cylinder assembly. Complete meaning cylinder, piston, lock, plug, valve, pin, and spring, assembled. I was going to use it on my build, but have decided to go with a later model instead. Was told this is Winchester, but don't know for sure. Need to get $125 shipped CONUS. Can accept ONLY discreet online payment (PP) +3%, or postal money order. Will be shipped Priority Mail, insurance $3 additional if desired. Contact me here by PM after posting an "I'll take it".