It is my understanding that Springfield Trapdoor rifles which were among the first with interchangable parts produced on a massive scale stocks were mechanically cut. Therefore the technology to do this must date back to right after the end of the Civil War or perhaps earlier. I not sure how the mechanics worked for turning stocks back then but I do know that one of the first "computer" punch card applications was for the Jaccard Loom used in the making of patterened cloth which also dates from the 19th century.
Perhaps someone on the forum can explain how mechanical stock duplication was done in the 19th century?
Jim
