Today I was trying to do a little preventive maintenance on the P19 I'm restoring, removing the SS 1/4-20 bolts which hold the gudgeons on to check for corrosion, and, of course, the last two bolt heads twisted right off as easy as pie, leaving their threaded portions still inside and flush with the outside of the transom. Am I completely screwed, or is there a reasonably non-destructive method to remove the bolts? Digging around the bolts to allow for a pair of vise grips has already occurred to me, but I'm hoping for a more elegant solution.