Hi Erik,
A schematic and service information for your RCA is covered in SAMS Photofact #323-11. This was published in 1956, which would probably make yours a 1955 model. These Photofacts can sometimes be found through local public libraries, or a fellow radio hobbyist may have a copy. Or you can order a copy direct from SAMS Technical Publishing at 1-800-428-7267.
Poston
:I recently came across a rca victor and it works but the speakers/controls need some tlc. I have no Idea how old it is -guessing the 50's. I do have have the paperwork for it though.The model # is 7-hf-3. If anyone out there knows more about this please contact me.
:Thanks!