Thanks guys. The is what I suspected but being a pre-newbie on these lathes, I'm very uncertain of any of my own ideas.
Working on this is much like working on antique cars, which I also do. After 75 years of owner-repairs and modifications, it takes a lot of sleuthing to discover what was original. I have a box of parts for a 1933 Morgan that came with the car but that never passed through factory hands.