While making up a couple of rail gun camera mounts, it occurred to me that the Delrin clamping assembly is really the only part that is machined. After that, you can pretty much add whatever aluminum or plastic arm you want to support the camera. For that matter, you could probably use the same clamp to attach a light, spare shaft holder, or whatever you could dream up.
So I made up three extra clamps in case anyone has a DIY project that just needs a little help to get off the ground.
They are black delrin, 1.5" high by 1.5" wide by 2" long, and bored to fit a standard 28mm rail gun barrel. The stainless cap screws are size 10-24, and are 1.25" apart and countersunk flush. The delrin drills and taps well if you wanted to attach something other than with the two cap screws and knobs. $35 each shipped in the continental U.S.