Virtually all M-1 carbines were rearsenaled or rebuilt at some time. It will probably be mixed manufacturer and upgraded parts, but this is the norm. Some carbine guys get real anal about matching this and that and do a lot of parts switching. From what I understand as far as originality, other than major parts, it may be impossible to tell which original manufacturer used small parts from the many differant subcontractors. Buy it and enjoy the fun.