With some 80 grit sandpaper and a mouse sander I sanded off the white paint and primer. After a quick clean up, I now have two bare metal surfaces to JB Weld together.
This was the part I have dreaded for weeks...putting all that JB Weld on the outer skin piece. I was slow and methodical using a popsickle stick, dribbling a thin line and a thicker one as needed.
Here's the outer skin with the JB Weld all applied....
....and here is the end result. I carefully laid the pieces together, eyeballed the right spot, using the horizontal lower panels to judge and slowly started clamping pieces together.
I had to lay the panel on top of a box while applying the clamps, so that the skin wouldn't be resting on clamps and push anything out of alignment.
I'll let this cure overnight and as I have done with the door pieces, use the Dremel metal brush to remove the excess JB Weld. Once that is done, the door and top trim pieces will go on.