The prognosis looks grim, ladies and gentlemen. Rather than a captive bolt, it looks like there is a plate with raised threaded collars that the screws thread into. I am thinking now that I actually twisted that raised area off of the little collar. Yesterday I tried to grip whatever was down there with a carbide stylus. Couldn't seem to grab on to anything that even felt like it was connected to the screw. This leads me to believe that there is just the little collar left on the screw, no flange left that could be possibly drilled and pinned. RATS! I may try some other approaches, but for now I am moving on. If I can get into the inside and somehow drill out a big hole, perhaps I could put a regular nut and epoxy it in place, levelling up the permanent part of the insole with epoxy or something.
Luckily, I got these shoes at a great price on clearance and had the foresight to purchase another pair. It is still frustrating, though, as the shoes themselves probably have years of life left in them.
Learn from my mistake and grease those threads.
Regards,
Raymond