Fixed the "hole" problem. It isnt perfect, but that's what body filler is for. Follow along. I used a 1/4" thick plate of aluminum to clamp on the underside to keep it all level. Small tacks till solid. Theres a little bit of warpage but not too bad. It's a trunk floor so no biggie. The good thing is now I will be able to use the correct 67-69 fuel filler tube rubber floor seal, and the tube will be positioned in the right spot for the fuel tank.