The American Museum of Natural History has an amazing historical photo archive, many of which show the setup and construction of their dioramas and exhibits. Museum props is props too!
Here is the curious evolution of the typewriter, with pictures. I’ve certainly had to provide my fair share of vintage typewriters for shows, but I’ve never had to track down one of those writing ball machines.
Haley Polak, a props artisan, had to build a mastodon skeleton. She used urethane foam and FoamCoat to pull it off.
Finally, here is a very cool photo set of an android being built. It has lots of great process shots of sculpting, molding and casting.