only suggestion is to look at drill planetaries I have looked high and low for a source of internal ring gears . making them would be done on a shaper or if someone knows of a newer process I'm all ears . My dad just put a hy-dash for a koering 6605 back together (I didn't get pics of it
) it has 2 walking plates driven by 3 cams . All the parts for that setup except the cams could be made on a mill . I could make the cams on the lathe with a 4 jaw . this is quite a project that I want to attempt some day
your doing a great job so far .