Thanks Paul, here you go...
TOOL TRAY FIX:
I used a 2-part polyester filler by Evercoat (#100417) to float the holes and fill the cracks. I originally bought it at my local paint and autobody supply store. Technically its a finishing glaze for blending, filling scratches, fixing door dings, etc. I probably should have used a heavier filler but its all I had on hand. Seems to be holding up just fine so far.
I used thin strips of aluminum for backing that I cut and trimmed to fit before epoxy'ng them to to backside of tool tray. FYI, the Evercoat filler is meant to bond to aluminum. I'm sure thin, rigid pieces of plastic epoxy'd to the backside of tray could be used along with a plastic purpose filler just the same way. Once the backing was in place, I pooled in the filler, let it set, then sanded, primed and painted to finish.
BASE TRUNK PANELS:
I used new elephant skin purchased from Veteran a while ago on top of 1/4" "finish" grade plywood (for a smooth topside feel). I couldn't find a true 1/4" ply to match original, so to firm up the panels and to add a 1/32" or so, I used metal tape in criss-cross pattern on the underside. This worked very well - better than I expected.
ALL OTHER PANELS:
I used 1/8" masonite like product and wrapped it with the same skin.
TAIL LIGHT SWAP:
I used a 2-part heavy duty epoxy to re-attach the plastic lenses to the frames.
Happy to provide more details by e-mail if needed.