I have an old pair of binoculars from the early 1940's which give a double image. I am sure that this means that they need collimating. The prisms are held in with springy metal straps, and seem to have shifted position.
It seems to me that in a lathe, we have almost everything needed to make up the mechanics of an Optical Bench; has anyone tried this approach?
What I have in mind is to use one of the laser blackboard pointers set up in the chuck and aligned to throw its beam at the centre of the tailstock, and then to mount the noccies on the cross-slide.