Update on fixing my cracked sidecase.
Plastic welding using a Weller soldering gun, with window screen and steel wool as reinforcement is going okay so far, though I'm only picking away at it here and there.
Kind of ugly, but not too bad, and it feels really solid.

If I really wanted to smooth it out I might be able to use some adhesion promoter primer and then a fairing compound or some bondo, but at long as there isn't any mesh or steel wool poking out to snag or scratch whatever I put in, and the repair holds, then I'm happy.

/blog