Today's somewhat unexpected score:
Matrox G200, AGP (thought it was G400...)
VLB drive controller/VGA card (I really do need a replacement VLB VGA card, so this worked out perfectly!)
Creative CT4620 SoundBlaster Live!
Asus TUSL2-C
...and yes, it boots up fine!
Acorp 6BX-7X-VIA86 "AT" form factor Slot 1 board
...which again - boots up fine, although it seems to be missing CR2032 battery holder
"J-656VXC" Intel (Socket 7) board ... so far in unknown condition.
and last but not least ... DFI PA61, Slot 1 mobo which has "NO" written all over it.
You'd assume that it doesn't work ... and yes - you would be somewhat right, I guess. That being said, I got the board to boot up by clearing the CMOS, although it hangs during the POST with continuous, short beeps and the keyboard doesn't respond. As if the keyboard circuit is fried or damaged. Oh yeah, and ATX power switch header doesn't appear to work, I had to start the board through CMOS reset jumper