Wheelwell help on 79 GT coupe.

Hello. I am new to the forums, and am looking for suggestions on dealing with the ever enlarging wheelwells, thanks to rust. Does anyone know if there are any other vehicles that have rear quarters that have similar wheelwells that match up well with the 2nd gen coupes. There are no patch panels anywhere that I can find. Open to suggestions, as my ratio white paint to rust color is dropping. Thanks all.