I've just noticed this topic which is interesting as I bought a 66K treadle earlier this week. Annoyingly, the cabinet has been painted white so I have many hours of paint stripper, wood dye and shellac ahead of me. As to the machine, I have totally stripped it, cleaned out the over zealous oiling using car oil mixed with plenty of fluff, polished up the (now) shiny bits and got her stitching a dream with a hand crank. So now to the paint stripping.....
As to screwdrivers, you need hollow ground screwdrivers, not standard household type. Very difficult to find as an actual screwdriver but easily obtained as replaceable bit screwdrivers. I use a bergen set which includes a small rachet which is useful in tight spaces, such as the screws in the needle plate, but you should be able to pick one up in any diy store. I even saw a set for about £8 in Aldi recently. Just look for a tip which is curved rather than tapered. Hope that makes sense?