[HO455]

I ran a tap through all the holes that have fixed nuts in the spare tire well. When I was wire wheeling and chasing the threads on the bolts for the spare tire well I was pleased to see all the bolts had a good coating of POR-15 on the end of the bolt. (Photo #1) This was a result of the void painting I did during the first pages of this repair thread. It was one of those things that you hope it did what you wanted it to but unless you cut it apart you don't know for sure.
Then I had to countersink the holes in the new plywood so the rear angle would sit flush. I couldn't find any countersink bits that matched the angle of the countersinks. So to get as close of a fit as possible it was mostly carved by hand. The first step was to draw the outside dimension. (Photo 2 red circle) Then drill a smaller countersink of the wrong angle to the needed depth. (Photo 2 green circle) Then I used a box knife to carve the rest to the proper shape. (Photo #2 blue circle). Photo three is the best photo I got of a finished countersink. It's not much of a picture. The same goes for photo four. It is the countersink bit that has too steep of an angle. From what I was able to find locally countersink bits all seem to be 45 degrees and the countersink on the rear angle is about 35 degrees.
One last step was to shave the sharp 90 degree edge off the corner of the plywood. The angle doesn't have a matching sharp bend. It is more of a very small radius. To get the angle to fit flush the top edge needs to be rounded off. I rounded the edge with a couple of passes with a small block plane. My first try was to sand it off with some 150 grit sandpaper, but the non-skid coating just laughed at my sandpaper.