So the sagging door on my 1978 Trillium
1300 finally got to the point where it was starting to rub the shell. Previous owner had used the glue and toothpicks. I had wanted to make the more permanent fix using plates on the inside and SS machine screws and nuts, and still may, but I needed an easier and quicker fix before taking off to Death Valley last Spring Break (concerned if it didn't come right off it would wear right through the gelcoat). So I removed the shell side of the offending hinge, drilled out the hole to 3/8" and packed it with PC Fix Marine Epoxy Putty (available at a Home Hardware near you), filling it bit by bit and packing it hard using a punch. After it hardened for 15 - 20 minutes I drilled small pilot holes, reattached the hinge and set the screws. I left the door wedged and taped overnight and it is rock solid.
I was so pleased with myself that I skipped and sang my way to the garage fridge
for a celebratory cold beer. However, one day during that DV Adventure I realized that my sagless door now made it apparent that my Bargman L400 bolt was so worn that you could open the door with it locked, but that's a story for another thread.
I'm sorry I only took a couple photos, but I think you'll get the jist of what I did. (last pic is at Potlatch State Park, WA on our way to DV)