Painting: Interior painting completed.

See here for my thought process on how I arrived at the method and materials I used.  It took 2 hours and 20 minutes to complete masking off everything (left).  Painting took about an hour (right).  The painting was done in my garage with the door open.  Using my 3M Low-Maintenance Half-Mask Organic Vapor, P95 Respirator Assembly, Medium, I didn't smell a thing.  In retrospect, long sleeves and goggles would have been helpful, as the overspray gets all over.

I wish it were a little lighter in color, but for using a total of 4 cans at $5.75/can, I will be perfectly happy.

Here is the interior masked off.  Because I painted the seat back brace and shoulder harness lugs red, I had to mask those guys off.

Various views of the painted areas.  This is prior to sanding out some runs and touching up some hard-to-access areas.

I decided that the Rust-Oleum Universal paint isn't very useful as the spray pattern induces a lot of runs.  And it turns out that the paint doesn't need to be perfect in unseen areas (e.g., under longerons, etc.) so it's okay to do without the Universal paint's ability to spray at any angle and just use the unsophisticated version.

A few photos showing the finish without the masking.