I am restoring a 1975 Firebird Formula and this core support came from that car. There was minor collision damage on the front drivers fender which dented the core support a little bit. As you can see from the pictures I fixed the core support with a hammer and dolly (it's not perfect but nobody will ever see it). The core support was sand blasted down to bare metal and I then applied SPI epoxy to seal it back up. I also reinforced the spot welds on the core support by applying new plug welds where required. It's stronger now than when it was new.
These are $500 new plus shipping. The price I'm offering is a steal when you take the time and materials into consideration (And replacement cost).