This keyboard appears to have been made in 1967, not long after Raytheon started making their own keyboard switches. But this keyboard is made by NAVCOR, not Raytheon. At this point NAVCOR had been in the game for several years already
keyboard:
Spoiler:
Looks like a previous owner has removed a bunch of traces... I am guessing they wanted to handwire a different output but changed their mind. Maybe I will finish the job
Diode matrix encoding!
The only chip has 6728 date code (28th week of 1967)
The brown transistor has marking 2N3638 703. rest are all 2N3643 CDC