Now that I have Manuel mostly reassembled, one thing is starting to make sense.
I removed the blanking plate from the opening below the screen in the inner bezel. When I reinserted the chassis, the top surface ("shelf") of the forward part is right at the bottom edge of the resulting hole. The full-height part of hole is about 5.1" wide and .6" high--just about right for a notebook CD-ROM (which typically is 5.04-5.06" wide by .5" high). The shelf is deep enough for such a drive also.
The 50-pin "notebook" IDE connector fits in with this also. The only thing remaining is to make a slot in the cover of the forward sheet metal for the 50-pin cable (which has power lines in it--remember the iopener HD cable?)
All that would be remaining would be to mount the drive (maybe foam double-sided tape), cut an appropriate slot in the outer bezel, and either let the notebook CD-ROM faceplate show through, or cut the tabs off the blanking plate and glue it onto the front of the faceplate to help it blend in a little.
Notebook CD-ROMS are not too expensive. One is http://www.essencompu.com/nupplysingar.asp?ID=2709
Once the BIOS unpleasantness is dealt with...
Kludgemeister (Manuel still boots after my unsoldering and socketing of the BIOS chip. It's just a shame that we don't have the right adapter for the BP Microsysems programmer at work...)