I can get most 3D movies on 35mm film, so it would be possible to do a transfer from those sources.
It would be a lot of work, most were over/under 3D (two images per frame), so they would have to be stabilised and converted to frame packed for 3D viewing on current televisions.
It would be possible if one had the time to then colour correct for better consistency between the left/right views, and even fix some of the misalignment errors on the originals.