gm 4106 rear window opening help

[4106-123]

im trying to recover the rear window in my 4106 i took out  3 fiberglass panels that were in with a gasket looked factory? the gasket was rotten and the previous clown who owned the bus (he knows who he is) covered the joints over and every other joint in the bus with with about 15 tubes of silicone caulk,which you cant paint,any way of course the gasket lip around the hole is rusted pretty bad so i cut a peice of 14 gauge alum sheet and tried to put in the hole were the gasket and fiberglass panels were. the problem im having is the hole has a compound curve so the metal sheet want lay in the hole properly. i had to beat dents it to get to to it to lay down. im painting the bus so i want it to look nice. im thinking about trying another piece over the piece i put in the hole as. i dont what to go the rear fiberglass cap route as i dont care for the looks. what have other people done to cover this area up and look nice? thanks george

[Len Silva]

Could you use the original fiberglass panels as a mold to make a new (single) panel?

Len