New brackets made up and the new panel is on the roof, used TRex adhesive this time around, test piece I did I nearly lifted my bench off the ground and it still stuck, I gave up first ................... So brackets glued to panel and put a big head rivet in once the goop had set, panel is glued to van roof and will either add a screw or rivet tomorrow when all set, my earlier panels haven't moved so process works .......... I'm just not fully trusting of an adhesive nor rivets or screws in a tin roof either on their pat malone, so chemical and mechanical shoudl cover the bases .......... even have a couple of holes in the roof part so adhesive will come thru bit like a stud ... and Big Mals roof after the hail repair years back is in dimpled alloy sheet possibly better adhesion than smooth stuff...
Unlike the shop brackets mine are 2 piece jobs, so one bit on the panel and the other for the roof and they are rivetted together, that way if you have to remove the panel you can without damaging the roof or putting extra holes in it .... The professional fit out panel they screwed the bracket to bottom of panel frame then it fastened to the roof glue/screw, so unable to remove panel unless you remove bracket from roof, dumb idea so my other panels the brackets can be split in half, just drill out some rivetts on the bracket leaving the roof mounted section okay.. ...
When the old panel dies fully I will just cut off the bracket leaving enough to attach another bracket leaving an anchor point on the roof not a patched hole, new panel doesn't fit I have points to fix a frame mount to if I go that way.