Just picked this up from ebay. It's the external keyboard variant of the HP 9826, I believe. I've opened it up and it's a maxi switch PCB. Identical internally to this set:
https://plus.google.com/photos/113845661925823397356/albums/5730992246714676497I'm planning on putting in a new controller.
Here's a shot I just took, uncleaned, just out of the box, so it's grubby.

[url http://i.imgur.com/k34gy3O.jpg]High res shot here.[/url] I'll post more shots as I work on it.
edit:
album here(oh, and is this the right subforum for this?)