All,
It has no literal "green keys", but I couldn't resist buying this the other day and it seems that you can connect it to an "RTTY loop", so presumably something like the Model 33? It can also do Morse! The inside is all discrete logic, with most chips having 1976 date codes. I haven't plugged it yet as I want to do some cleaning/checking the power supply first.
I am curious to know if anybody is familiar with this device.
The pictures below are (obviously) before any cleaning whatsoever. Here is a link to more pictures:
-Erik