I have this machine sitting at my home in Cape Town. (I still haven't taken a look at it yet)
It's missing it's hard drive, as I acquired it from the DOD, so they wouldn't let it go with the drive in the machine. (So I'm going to have to get one of these bad-boys for it!.)
I also have the original keyboard for it, but lack the original EGA monitor. (I will have to see if I can get my hands on a fancy ISA VGA card for it.)
It's a really cool system and definitely one of the most solidly built systems I've ever encountered.
The motherboard sits in a compartment on the underside of the machine, and with the top cover removed you have access to the power supply, disk drives and ISA plane, which is kind of like a horizontally orientated ISA riser card.
The machine appears to have an ISA memory expansion caed installed.
Here are some details on the machine's motherboard: (I spot a Dallas chip!!!)