newbie
Thanks for being gentle. I was thinking more like "dumb a$$".
1) Stop using the drive with the wallet.dat file as an OS drive
2) Place said drive into another PC
3) Run a program to find deleted files (I use File Scavenger - worth buying if you're talking about a few BTC)
4) If you are able to find an older version of wallet.dat then you have some hope. Backup that file onto 2 USB drives
5) Install new Bitcoin-qt client onto a PC and let it run for a minute, just long enough to finish installing and creating a new wallet.dat file
6) Replace that new wallet.dat file with your backup from one of the 2 USB drives (again under App Data)
6) Resync and cross your fingers
I couldn't put the drive into another PC, but I did run File Scavenger. It was only able to find the same 88kb file (compared to a freshly-installed file size of 80kb) that I already had found and used to replace my Qt wallet, so I didn't buy it to access that file. At this point the only remaining question is why the wallet's file size is 8kb larger than a freshly-installed wallet, but the wallet appears empty - nothing. Not even my original address, which I would think would show up. If anybody has an explanation for that, I'm curious, but I think that bitcoin is gone for good...
Ah, well, live and learn - I don't tend to make the same mistakes twice...