Looking fro Specs Freq. Elec. 5654A osc.

I'm casting a wide net as my inital search has proved unsuccessfull.
I am looking for the interface specifications or a manual for
a Frequency Electronics rubidium oscillator, model 5654A.
If anyone can give me this info or can give me an idea where I
might get it I would be grateful.
It has a 50pin 1.27mm pitch connector, and GPS signal in/out,
  so I think they must have been installed in some OEM equipment 
(telecom ,measurement, survey, astro.. for ex.).
If anyone knows what they were used in , that may help aswell.
Please copy me directly as well as replying to the NG.
Thanks,
Mike