Traced the curve from the turtledeck skin onto this retaining strip and trimmed the edge. It's a nice match for the turtledeck skin now. The other edge is still rough, but I'm not yet sure how wide to make it.

Drew a sketch and did some simple trig to figure out that the strip needs to be 1.54" wide.

After trimming and fitting that first strip to 1.54" wide, and confirming it fit well (except at the inboard end where it was ~1.75" too short), I used it as a pattern to trace out another on a fresh strip of aluminum. Much trimming, filing, and sanding later, I have the (hopefully) final strip made for the left side. Here's a view along the inside. There's still lots of work left to do on this part. I need to segment it into a bunch of tabs...each of which will be joggled to accomodate the .175 thick canopy rear window. Then drill through all those tabs and the turtledeck skin, and debur, dimple, prime, rivet. The good news is that I should be able to do all these with the squeezer. That is, of course, if it proves possible for me to install the window after riveting. Otherwise, I'll need to rivet them once the rear window is in and that seems pretty dicey. We'll see.