Removing the flange

After discussing it with other vintage boaters, the best way to go seems to be to cut off the 'flange' of fiberglass on the inside of the transom. That will leave enough room to flush fit a third layer of MDO, and then I can glass/epoxy the entire front and mold it back into the hull. I'm also going to get some 'kitty hair' which is fiberglass impregnated filler or bondo, and use that to fill in the corners around the new wood. All together that should make a stronger than original transom. I just need to get some new fiberglass cutting disks for the dremel, find my dust mask, and get cutting!