I was looking for the taper for the Roland Camm-3, came across this one ebay.
Not sure if a drill is worth considering, as an endmill is going to do whatever needs doing on thin stuff, and larger circles would just be programming.
But… If the measurements check out, that could be used as a guide for a next step.
Assuming (ah yes… dangerous) that the spindle nose is hardened/ground… then a soft collet should theoretically be able to be fabricated.
It would make a good intro to lathe project, turn to diameter1, turn to diameter 2 LH, cut taper, polish, drill undersize, ream, part… then slottting. Then qc and measurements… Odds are it’s going to be far more discards than keeps. Looks like the collect is going to need be smaller than the root of that 3/8 thread, so perhaps 1/4, and 1/8 are the sizes to add. 1/8 being a challenge with a really thin saw?
The other thing to consider, engraving wise, is single flute cutters… the pantograph engravers had a bit of info on that, basically it seems an easy shape for cutter grinders… but needs high spindle speeds. Computer is laggy, will research 3/16 shank engraving bits also. In a bit. (ah… had to say it)
I am going to assume reguardless, some pre loaded collet and tools combos are still desirable.