That looks about right from here
As a matter of fact, I was just out taking pics for you of my '79 end sills to help. But you have it figured out now.
It was a surprise to me that it tilts forward at the bottom. But that is how it is supposed to fit. The center panel of the sill assemble is cut on a slight angle. You fabricated that part. If you were to have used it, it would have been a bit easier to picture the end cap fitting. If you look closely on the cap, there is a jog along the inner edge of the vertical face of the end piece that overlaps the sill flange where it was spot welded to the rear inner fender. If you (I) weren't mindful when welding that flange, it will cause some fitting issues that may need to be adjusted.
You are making good progress. Me, not so much. I'm on day "n++++" of figuring out the A/C ducting. I finally have it figured out now and the box is built. All I need now is to add the two 2" ports on the side of the plenum for the outer vents. Then I can move on to figuring out the type, size and location of the fuse/relay panels, PCM, Cruise module and HVAC hoses through the firewall. I recently discovered that the location of the PS motor will interfere with installing/replacing the brake master cylinder. Always something to figure out.
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Chuck.
“Any suspension will work if you don’t let it.” - Colin Chapman
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