Ok... pics are up (sorry, no risque terminal pics).
That's ok, my tastes run to hats, anyway...
Go to <http://www.mythtech.net/terminal>
There are two terms there. One is a Wyse something (maybe a
60 based on pics I just saw on ebay).
The Wyse does indeed look like a 60, but I think the 55 and 35
look similar. Had it been a 50 or a 100, it would have been a
more obvious identification.
Can you get it into Setup mode? There may be a clue there...
it's something like Function-Setup, at least, it is on the 50...
-dq