[Premium-Rx] Research on 1990's Watkins-Johnson receivers

[no name]

 Hi,
I am doing some product research and looking for a manual on the Watkins-Johnson 8711 or 8711A.  Or, a manual on the HF1000, 8710 or 8712 would be useful as the 25 KHz IF DSP technology seems to be about the same.  I do have the data sheet on the 8711 and 8711A but the block diagram is not very detailed.  Does anyone know where I can find or purchase a manual for any of these models?
Specifically, I want to understand if the 25 KHz IF signal in these radios is split into I and Q channels, and if bandpass filtering and detection is all performed at 25 KHz in DSP.  I don't think this is a homodyne back end in these radios.
Or, does anyone know of any other receiver which actually does produce I/Q channels, filtering, and detection at a low IF in DSP which would have been introduced in the early 1990's?
Thanks very much for any ideas or comments!
rk