[Milsurplus] AN/FRR-51 Wazzit?

[Nick England]

Anyone ever heard of the following?
AN/FRR-51 Dual-diversity HF receiving system with 10 channel auto-tune
(0.5-32 mc)
components -
   R-792/URR receiver (2 ea.)
   CU-560/URR antenna coupler
   C-2087/URR receiver control
   C-2086/URR remote switching control
   CV-116/URR dual diversity FSK converter
   CV-395/U Signal Data Converter
   CY-1119/U cabinet
Googling didn't show up anything except on the CV-116 and I know what that is.
Above info from a September 1956 Nomenclature Card according to a Navy
ESO publication