First I dropped some Tri flow on those screws and applied heat via the hair dryer. Then I applied PB blaster and heat. Then I got out the Kroil and applied heat. It really stunk in my shop with all the petro chemicals getting warmed up. I think it might have finally been time and the Kroil that loosened the screws. I got them out, managed to hang onto them and removed the spring. Too big. Doggone it! (If you really believe that that is all I said......ask my friend Betsy, or better yet, my mother, about my potty mouth. Actually almost anyone could tell you about my potty mouth. Shoot my 12 year old son was known to say "Language , Mother." He still does, now 21 years later.)
So I have concluded that these drive springs are not interchangeable. I found one at this website http://sewingmachine221sale.bizland.com/store/index.html Just hope that it fits.
I won't order it yet. Betsy claims to have some parts machines. We will see. Dang (there I go again, I am as bad as Ethan Allen!) it will be a PITA to remove.