Where's the Baldwin proof?

[Traintime]

Historical sources continually report that Philadelphia locomotive builder extraordinaire Matthias W. Baldwin held an apprenticeship, was trained and employed as a jeweler, and even acted independently for some years as a silversmith during the Coin Standards era. One source indicates he was commissioned to build a working model of a steam locomotive which then led to a request to build the real thing. So where are any surviving works, marks, or stamps related to his period of silver work? He was successful, so wouldn't he have held a stamp for his own mark?

[Aguest]

What's this about Baldwin not completing his apprenticeship because it was basically indentured servitude and working conditions were too unfair? :::

Did Baldwin basically invent the process of making rolled gold plate?