Thanks for the info
@Brent H ! That makes complete sense. My 1120 does have a tapped hole in front of the input gear boss in what seems like the correct location to secure the banjo.
A friend of mine let me know that he has a 3D printer now so he's able to print for me. That could either be indexing plates for a dividing head or the gears themselves. I believe I've got enough information to develop a drawing for the banjo that should work, even if it's not a match to an original. That's probably where I'll focus for the time being and get some drawings/models sent to my friend for the following gears to test everything:
16DP 14.5PA
- 68T idler (wide)
- 48T (with hub)
24DP 14.5PA (or Mod1 20PA)
- 127T
- 80T
- 50T
This is seems like the fastest way to get up and running. I'll still need to make the standoff/shaft for the banjo to mount the intermediate gears.