Per Ryan's and Mark' Posting:
Perhaps one of the stock makers will come in on this.

Could a stock be carefully taped prior to using it as a pattern and thus protect its finish? It would add the thickness of the tape to the final version, and would round some sharp contours, but those details would all likely get attention in the actual finishing of the copy stock.

I have several custom stocks that would be nice to have duplicated if it could be done without sacrificing the original's finish.