I'm looking at installing a dummy M14 fire selector parts kit on a M1A I'll be building. The parts would be fastened to the stock itself, and not to the receiver as in the original design, so they would be non-functional and serve only in a cosmetic role. My question is, is it legal in OK to own these parts which come from a demilled M14, or would I need a tax stamp? Any one gone this route before?