[Bushwacker]

Blue 197320, my 72 Seafari has same disease and I'm in process of replacing scupper tubes. Try Dremel wheel #542, Carbide cutting/shaping wheel. It's about 1.0" dia, so is small enough to fit thru f/g hole. If you use the dremel flex cable extension, should be able to carve out most of the rotted wood. My starboard side was ok, no rot but had 1-2" of rotted wood on port side; got most of it out just by just prying w/screwdriver. Have soaked w/alcohol and will seal w/git rot after it dries out. Have figured out a scheme to fill hole w/thickened epoxy & have pilot hole for redrilling: get a 1/2" pvc threaded union and use belt sander to taper one end down to ~1" diameter so it'll fit into hole from bottom. Screw a 1/2" hard grey plastic pvc riser into tapered union and put into hole from bottom. Will use 2x4 & bottle jack to hold it in. Riser wants to be about 2" long, so end is about 1" below top of hole, to provide access for epoxy. Can use a 1/2" dowel rod into top of riser to center it. I plan to put epoxy mix in an empty caulk tube from BOW and pump it in with caulk gun. Will leave dowel rod in place till epoxy cures, then cut & redrill hole with conventional solid 1" drill bit. I figure the soft core of wood/pvc will help it pilot ok. Haven't actually done this yet, but have thought it over for couple of days and believe it'll work. Will probably try it in next couple of weeks. Good luck!