I lost that auction by about a dollar! If you want to sell these, I want 'em!

On the question: Looking at the photo of the McMahon brake and comparing this one reveals that they aren't of a related design (check out the cable entrance and the height of the arm pivots as well as the three piece construction of the Star Trek logo brakes). These are probably a proof of concept prototype that never made it to production and they're _very interesting. The most useful, telltale info might be had by examining photos of the internal mech and I'd love to, can't wait to, see.