The film availability makes me wish there were a 120 film or 70 mm film camera from that era that could do full 360.
Can a Cirkut #6 be made to use 60mm or 70mm film, with appropriate lenses of course? If so, that would at least keep the small Cirkuts desirable.
The downside(s) I can imagine are two:
1. Have to have appropriate gearing made for such a wide-angle lens.
2. Any non-smooth spot in the drivetrain would be more visible on small film.