I cannot imagine how one would fit a distributor to the M42. You would need to do some significant machining on the head, make custom cam gears and...well, it would not be worth it. You might as well try to find a running S14, or build up a crazy M10. Those would probably cost less than trying to convert an M42 to be distributed, which is pretty unlikely to even be possible anyway. Solid state ignition was invented for a reason lol...
People have run carbs on the M42. Again, I am not sure why one would want to, but a small number of people have done it.