Well, this is an interesting turn up for the books. It turns out that while many photographers are trying to adapt their old film cameras to their shiny new Sony cameras, one photographer, Alexander Gee, was doing the opposite. He wanted a film camera that would work with his modern Sony E-Mount lenses.
LEX, as the camera is called, is a one-man operation, and it seems to have come quite far already. Gee plans to make LEX fully open source, once complete, with much of the camera being easily 3D printable and easy to modify. Don’t have Sony lenses? No problem, just modify it for another camera mount and print that out instead.