I have been coming here for quite a while to learn more about tool repair and hand woodworking, so I'm glad to finally join and become part of the community.
I recently acquired a Millers Falls No. 61 spiral screwdriver in good overall shape, and I found that the ratcheting mechanism occasionally binds up (I have to backdrive a little to free it and continue moving). It was already well oiled, so I figured some gunk or wear on the pawls was causing it to jam. While trying to open the ratchet mechanism (patent US 1578866 A) from the front end I reached this part that was threaded into the body (Number 21 in the patent):
MF 61 Split Slot Face.jpg
The part is seized (it appeared the last person to tighten it applied enough torque to mangle the slot), and I tried to free the threads with penetrating oil and torque on the slots (a single flathead on one side, then made a sheet metal spanner that fit into both slots) with no luck.
I have found a lot of information online for the North Bros. drivers, but I have had little luck finding information on disassembly or repair of a Millers Falls driver. Does anyone happen to have ideas or experience of how to remove this cap, or if there is another way to access the ratchet mechanism for cleaning and inspection?
Thanks!