Here are some pictures of a motor I picked up a while back and am just now looking into.  It's a Model 504 motor by "Georg Jensen Denmark" that's spec'd to 24fps.  I was going to ask if anyone knew anything about it because I could never find anything via google (except that a guy named Georg Jensen makes lots of sterling silver items!), but since I last looked, Pacific Rim Camera has put up a very helpful brochure: https://www.pacificrimcamera.com/rl/01130/01130.pdf That answers almos