This HP71B is used to control a HF suitcase radio, decrypt and print messages.
I saw this on the Collins radio stand at the Amateur Radio Pacificon conference on Saturday.
I grabbed a couple of photos meaning to take more detail later; but by the time I returned it's owner had gone, so I don't know the model number.
Thought it might be of interest to others here.
Seems similar to other sets of the era shown at the crypto museum
Crypto Museum

Neat!
I found an environmental case with an antenna, transmit receive hand made board all hard wired into a 41cx and HPIL printer at a flea market.
Looked like a portable weather station that you could leave unattended for awhile. I still have the case, but removed the printer and 41cx from their imbedded position in the foam that was holding them.
Some creative types out there. Wish I had documented the entire project but I needed the printer and 41 at the time.
Cheers
I don't know about this specific one, but in many of these sort of suitcase setups that I've seen, the computer (HP-71B, Panasonic/Quasar HHC, Sparp PC-14xx, etc.) is used to program (configure) the radio, and not as part of "normal" radio operations. Usually the radio has any crypto built in, rather than depending on a separate computer for that.
It looks like there's probably an 82164A or 86165A/66A hidden in the suitcase somewhere.
It certainly would be interesting to get more information about this particular configuration, if one shows up again.