cannot locate documentation on SCA 9190 receiver

[bpasok]

I just picked up an old tube type receiver. It is a 'Stereo Corporation of America' receiver Prestige model 9190. It uses 6BQ5 outputs and has a large transformer between the two smaller output transformers (in addition to the still larger power transformer. I am hoping that there is someone out there that has heard of this unit and can help me with an owner's manual/schematic.

 

[bpasok]

update

I did find a couple of examples of a similar amp (not receiver)... with the three channels and 6BQ5 outputs. They are referred to as systems made for a chain store. I have not found a schematic. Any help would be greatly appreciated