Once I had proven that my laptop would boot and basically run, I ejected the DVD that I'd managed to cram through the misaligned loading slot. It had a tiny crack in it, which I'm sure it got from being jammed in and pried out. This was madness! I wasn't going to go for a year with a disc-breaking optical drive!
I re-opened the machine, having now determined just which screws actually keep the keyboard in place, and unscrewed the three screws that entered the main assembly through the upper shell near the DVD slot. They were of the "longer, wider head" variety. As I got them about halfway out, I slid a DVD in and out of the slot, and it felt exactly right. I replaced the screws with the "shorter, wider head" variety, and everything was fine. I reassembled the whole system and turned it on.
There was a loud sliding noise, then a crack from the drive, presumably as the laser head zoomed along into a home position. Who knows! Despite some minor anxiety about the noise, everything worked. I replaced the four hardest-to-remove pieces, which I'd left off during this whole ordeal: F1, F2, F11, and F12.
I had a fairly recent backup of my system on an external (ugh) USB drive, which seems to max around 12 Mbps. I keep daily backups of everything that matters, except the contents of ~/Library; I'll need to remedy that oversight. Maybe Carbon Copy Cloner, or something, will work once I have a final Tiger. I'm even considering using
In the meantime, I'm just happy that I didn't need to spend any more money on this problem.