skipd1:
The item you are missing is the Index Dial Spring. It was used on the 12 inch High Speed Shaper and on lathes from 12 inch through 20 inch. It is made from #26 music wire and bent to a special shape after bending into a circle and grinding the edges. This has not been a stock item for over 35 years. I was able to locate the drawing for this spring and if you would like to make one, I can sell you the drawing. The drawing number is B11-183A. Contact me for copying and shipping charges.
Hendeyman