2nd Gen Coupe Quarter Panel Patch

I cannot find any company that makes 2nd generation coupe patch panels for the lower rear quarter (between the door and wheel arch).Do these exist or will I have to fabricate? (thats not a problem,but I would rather get something pre-made and "perfect").Seems these cars rust in the same places:rocker panels,lower doorskin,rear wheellips(thankfully these arent rusted),and the quarter between the door and wheelhouse.Lovely GM design,even a car with only 36,000 miles rusts in almost all the typical areas.