[Franks 72]

I had a similar problem (barn door application but I suspect construction method is the same) The rear tail pan is a complex piece to repair but can be done. Mine was paper thin with rust. I removed it completly and drilled all spot welds which hold the "cover" and made new pieces with a brake and welded up new assembly .The result was not ideal cosmetically since the spot welds in the cover are now plug welds and ground smooth, but it is stronger than what was there . Probably best to try and find someone parting out. If the tailpan is rusty , check the main crossmember for corrosion. It may be paper thin also but harder to see ! Hope this helps!