While the right-side panel was simply cracked, the left-side had its lower half damaged beyond repair. Luckily, I had another left-side panel with a mismatched upper half from an F2 model. The obvious solution was to mate the good pieces into one usable left panel.
After carefully cutting both parts across the middle on an identical line, I plastic welded the halves together.
Here the two left-side panels are pictured after making my cuts. The black pieces were originally together, as were the bluish-colored ones. The parts on the right will be tossed and the left made into a useable piece.
Here, the left panel is joined and the right panel has its welding repairs made. The welding repairs have been ground smooth and the first coat of body filler is applied.
Here's a look at the welded back sides.
(click on an image to enlarge)
I didn't get a separate photo of the finished parts, but here they're fitted to the bike.
Job done!