After 60 years of messing with Lefevers, I have found that the initial breaking free of the screw is best done with a punch that matches the contour of the head of the screw. I have that baby around here somewhere. The punch is struck with a hammer, hopefully breaking the seal. To be honest, I have only had two Lefevers that needed such attention. I would rather use the "hardened pins inserted into a block" as a wrench rather than a carved out screwdriver blade. The pins created by a filed screwdriver are way less than round and fitted to the holes and they aren't very hard. Dewey Vicknair did one particularly stubborn example, but I never asked him how he did it.
