That is really interesting because I have been curious, and asked the question here and on other sites.... who or what companies actually made the molded buttplates for vintage guns??? I've always assumed the various gun manufacturers outsourced the production of their buttplates to some subcontractor, but never found the answer.
Today, we would expect to find them made very quickly in quantity by the injection molding process. Or maybe they would be cast in silicone molds out of poured urethane resin for small batches, as we see now from those who produce reproduction buttplates. I hope someone can shed some light on what the molds were made of a century ago, who made them, and what process or material was used. Some buttplates appear to be made of gutta percha, but obviously other materials were involved.