Used some gorilla tape to attach a section of PVC pipe to the skin.

It has a pretty decent curl now. Not quite the full curvature needed to follow the sub panel and firewall, but it doesn't take much force to pull it down the rest of the way.

Right side drilled to the sub panel and firewall. Note, in order to ensure the firewall was in a flat state prior to drilling, I held a nice, straight piece of oak up to the firewall. It was long enough to span across both of the rib pairs out to whichever tab I happened to be drilling.

This one firewall tab has a bit of a weird overlap on the side skin. The other side is like this as well. Also, because the flanges of teh firewall follow a continuous curve in the area of the top and side skin, I think I'll make up a little shim to ease the transition of where the top skin overlaps teh side skin.

Left side drilled.

In order to match drill the holes in the longeron to the right side of the top skin, I needed easy access to the inside, under this skin. To prop the skin up, I clamped a C-clamp to one of the garage door stiffeners, and used a string and spring clamp to hold the left side up.

Hard to see here, but I'm drilling on of the side holes from the inside out, through the existing holes in the longeron and side skin. I used a block of wood to backup this skin when drilling each of these holes.