I've been trying for a few weeks to coax out the big, countersunk flathead body screws that attach the hinges, door posts, lower cab mounts on my '40 GMC. I've tried penetrating fluid (PB Blaster), etc. but still not having much luck. Last week I resorted to drilling a couple of them and using easy outs but all I have managed to do is twist the screw heads off, leaving what's left of the threaded part of the screw still in the hole. I'm considering just drilling the screws all the way out and re-tapping for the next size up or I've got a guy who's a whiz at building up the screw hole and re-tapping to the original size. Does anyone out there have any other (better) ideas for this?
Thanks

Neil
1940 GMC 1/2 Ton