Major Surgery on the back window:
The back window lower channel and corners had been rusting away for a long time. The previous owner had used tape and plastic filler OVER the rust. This made the rust much much worse. There was more there than originally thought. The PO also cut out most of the package tray for some reason, so a replacement had to be sourced.
Here is what was started with:
After the back window was out, you can really see the missing metal and rust. What a mess!
Here is the replacement metal that was sourced. The filler panel and corners came from Auto Metal Direct. The package tray was donated by a junked 68 Coronet.

Started cutting out the deck filler panel, found more rust, the car is pretty much rust free except for the area around the back window for some reason.

Welded in the new panel:
Cut the spotwelds on the old package tray and removed what was left of it.
Here is the replacement package tray and supports welded in:
Started next on the left rear corner of the window:
I forgot to take pics while doing this side, but here it is mostly done, it just needs a skim coat of filler to smooth the welds. It was the same steps as below.
Here is the right rear window corner repair:
Welding and grinding complete, its ready for a skim coat of filler to make this corner perfect.
More pics of the progress to come!