Progress is slow but I'm still going.
Both crossmembers in the rear were pretty rough and I after thinking about it for a while I decided its better to replace them rather than have the gas tank fall out or the rear frame twist. I had to replace the lower portion of the tail end of the frame and add material where it rusted away.
I'll probably end up working down the frame rails making patches/adding plate to the outside before I reach the front crossmember. I've considered making a x-brace between the crossmembers but that can always be added later.
My LSPV was frozen and the rod from the valve to the diff was bent out of shape from lowering so I decided to replace it with a Wilwood prop valve. Install was pretty straightforward; remove lower line on LSPV going to the forward tee junction and plug junction with a bleeder, connect upper LSPV brake line to flex line on diff, mount prop valve and fit the brake lines In/Out.
I still have to bleed the brakes and figure out which of the rear shoes is dragging but its another item of the ever-growing list.