I spent at least an hour yesterday with a drill, impact screwdriver, and propane torch trying to remove the sludge trap screw plugs from a crankshaft. Finally gave it up and last night searched the forum for suggestions. Sorry I don't remember who posted the instruction to drill and use a #5 screw extractor, but I'd like to extend my heartfelt thanks. It worked beautifully.
I have been wondering why I was doing this, because the crank bearings, rod bearings, etc all seem to be in excellent condition. When I saw the crap in the sludge trap, I felt much better about having gone to the trouble. All clean now, and just ordered new plugs and a gasket set. Hopefully they arrive quickly and I'll get this engine back together.