Re: 1979 Imperial
Bruthu Bear isn't lost....I was having my doubts to be honest....Hope you are able to get that bolt out. Is that in some aluminum type alloy or steel? It probably had some corrosion and was binding the threads up. Seeing that the slot trick didn't work, you might try an extracter like JB suggested. Use a punch the make a center mark though, just in case it still doesn't come out. You might end up having to drill it out like you were taping it for the first time. Be careful if you do try to run a tap in it. Small partial turns and back out all the way, then blow some compressed air from an air nozzle to clear the chips out. Slow and easy and it might come out alright. Or....you could drill it out for the next bigger size bolt. Not that I think about it, I think that is what I would do if the extractor doesn't work. Make sure you don't break the extractor off too. Then you are SOL.
Happy Easter!
... Tomorrow I'll grind them down and spice in a small layer of 1807, and finally finish the transom by using two layers of 1708 for the skin... Overall I'm very happy with my results... The stern of this boat should be very strong! 
