Regarding the empty slots of the mainboard and that old style cpu grill shown in picture number four it looks like one of the first 601 PPC carrier cards for development puposes.
J
Interesting find, I wonder what it was. It has an Apple dev number and barcode on it, so they might know who it was for, and possibly what it was as well.
Amazing what kind of neat stuff you can find digging through the electronic trash of our modern age.
Chef