> To those of you who are able to loosen/tighten these nuts without
> damage... Do you just grind down a thicker screwdriver blade? Do
> you make your own screwdrivers? If so, what do you use for the
> steel blade?

Use a one inch by six inch piece of saw blade. File split nut profile in
one end, regular profile in other end. Make a nice wooden handle
sandwiching the blade between the two handle halves and riveting the
same to the blade, leaving about 3/4 to one inch of each end exposed and
you now have a saw nut screwdriver.