The chances that your carbine is "all original" is about zero, even if it sports the original parkerizing.
The US Military had a tendency to do depot level repair wherein large quanitities of like weapons are stripped to subsystem level, and separated into like piles of parts. The rebuild process then starts, where the repaired/refinished/reassembles are reintegrated into complete weapons.
Thus, the mix and match approach guarantees parts of various vintages and sources winding up in given arm.
The real issue that separates collectable carbines from the "mixmasters" are two items:
1. is it early enough to sport the barrel band WITHOUT bayonet lug, and is it early enough to have the "flip type" rear sight?
2. If so, does it still have both of these early features?
If the answer to #1 is "YES", and #2 is "NO", then the entire idea of making it "original" is problematic. Given that, just don't worry about the finish, and enjoy your "mixmaster shooter".
