[lxdude]

Apparently any m42 glass I get has to be preset aperture and not auto like later m42, unless there is a way around this?

All screw thread Takumars will work, as the auto lenses have an A/M switch. Lenses can be set to any f/stop, and moving the switch from A to M will close that stop, the same way a preset lens works. But they are auto diaphragm on A.

Auto M42 lenses without an A/M switch will have to be used fully open, or hold in or jam the pin somehow, making it a manual lens.