if you're still looking for the camera back adapter, I have one, but as my Precision A is complete i.e. all the correct attachments, lenses, carriers,original instruction manual, all condensers (1,2,3) etc, I cannot break it up. Also there are two camera backs, the 35mm and bantam828. You need the camera back adapter in order to use the camera back. The camera back adapter also is used for the 21/4x31/4 picture taking (rather than the copying mode the 35mm and 828bantam backs are used for) back i.e. studio type use when a lens/shutter combo. is mounted up front. This Precision A was truly a whole camera system, modular in concept, from the outset. It was and still is, an elegantly conceived and wonderfully executed (finest of materials.....form follows function, photographic masterpiece of its day. With the Medalist 11, and extension back, cut film and film-pack adapters, one had as complete a photographic system as could be had in the day. It wasn't 'till the Blad, that anything eclipsed this combo. I have most everything, even the tilting easel, in boxes somewhere and am thinking of contacting the Eastman Museam to see if they already have a fine copy of this (these) examples.