Good leads, thanks!

Mainly I was wondering if there was a hobbyist industry that I'd missed. The idea of modern materials and techniques used to implement hand-powered equipment. Also, by pricing this stuff, I can get a rough economic model put together.

Historical sources have proven very valuable. Lowell Mills in particular. Its machine shop was built to support the textile mills, but then turned into the center of its own industry as the demand for machinery of all kinds increased.