Well, I grew impatient enough to go get my own MailStation, open it up, and take some pics!
It's not very exciting, but if you're curious:
It's a very small "motherboard". (Remember that this thing runs on 3 AA batteries, so it's no x86.) Seven outside screws, and a few more holding the main board in. The display is connected by rigid ribbon, as is the keyboard.
I've labeled the most significant parts on the board. It goes something like this:
8Mbit (1M x 8) CMOS Flash Memory. 5v r/w/e
RSDRD 3SI176 0A F99260307
Custom ASIC?? Any ideas?
MX 27C1000MC-45 (Macronix)
1M-BIT (128k x 8) CMOS EPROM
Slow-speed SRAM 1Mbit (128k x 8)
Low-power CMOS SRAM (5v) 256kbit (32k x 8bit)