Removed the base of the dash today. The drivers side corner had been wet at some point in the past. When unbolting that dash hold down the nut and bolt were frozen and I ended up pulling the bolt through the mounting point.
About half of the screws holding the decorative dash back pieces were rusted in both corners, so I needed to remove with needle nose pliers (screws are straight wood screws).
The bottom of the dash on the drivers side was delaminated so I spent the afternoon starting some repairs.
I carefully peeled the vinyl back from the section to be repaired and cut the top and bottom sheets out of the way with a utility knife and then made some filler pieces using maple veneer. The veneer patches are glued and under pressure tonight and the three remainig layers of plywood were glued and clamped. If all goes well tomorrow I will plan on gluing the patches in place to stabilize the corner.
I do need to find a replacement for the nut that is supposed to be captured in the bottom of the dash. It is solidly frozen on the dash bolt and I have it soaking, but dont expect it will survive. If anyone has any suggestions or has one please let me know. The top picture is the middle hold-down and shows the nut captured in the wood dash, the photo below shows how the wood is blown out when the frozen nut pulled through the wood.