TM 11-858.pdf  Instruction Book for Radio Receiver R-392/URR.  29 June 1954.
TM11-5820-334-20P.pdf  Organizational Maintenance Repair Parts and Special Tools Lists for R-392/URR.  July 1977.
TM11-5820-334-34P.pdf  Direct Support and General Support Maintenance Repair Parts and Special Tools Lists for R-392/URR. July 1977.
TM11-5820-334-35.pdf  Technical Manual for Radio Receiver R-392/URR.  21 August 1961.

These files are made available with the compliments of August Johnson, KG7BZ.
The scanned R-392 manual is courtesy William L Townsend, WA8ULO.