Frank, are your collets similar to the one on the left in the attached pic, except for the R8 spindle? I believe it is called a collet chuck, but I couldn't find any for R8. I found a 1/2 straight to Jacobs chuck adapter for $16.52, and R8 collets for $18.28 each from McMaster, so I think I'll just get the adapter and a 3/8 collet for now, along with the V-belt. Plus, my friend has an account with them, and I can just have my stuff thrown in with his next order.
I found that my old rotary table will fit!
It's a 9" Alfred A. Troyke unit, if that means anything.
Also, I checked the patent date on the tach: Mar 28 1905