Me thanks you mean oversize rear mail seals so you could grind the seal area down to smooth it up, correct?
If so, due you know about the original rope rear main seals that Ma Mopar used forever before switching to the new style neoprene and Viton formed two piece rear main seals?
They, the rope type, should work well on a rusted and pitted main seal area as long as the rust is remove and polished down some to make a smooth sealing area for the old style rope seals to seal against