This mornings endeavors. I secured the panel while clamped, with drill screws so I can put it right back in the same place after every removal for fitting, prepping, etc.
This is the left corner, that is badly out of place for the dash panel.
I removed the panel and made a pie cut 8" long and 3/8" wide at the outside, tapering it to the inside.
Clamped it tight and drill screwed it in place.
That's the first modification. The entire lip needs to come down for the dash to lay on top, but after tapping the end down, it started to buckle, which I expected. Bending that lip down decreases the radius and the extra metal has to go somewhere. I'll need to make pie cut reliefs every 3-4 inches to get it to cooperate...
Before...
.