RCA M-12296
Three microphone preamps - 6JZ tubes
Two (one stereo) phono preamp inputs - 6JZ tubes
Power amp - 4 6V6 tubes (one broken) and a 6SN7/GTB with an RCA 5U4G tube for the rectifier
I don't know much about the transformers but they appear original. There's a burnt resistor on one of the pins of the bottom left 6V6 (right above the 6J7). The amp powers on. I did not attempt to pass signal through it. After finding the broken resistor and broken top of the 6V6 especially so.
Includes photofact pamphlet containing detailed parts list and schematics. Also includes replacement 6V6 GT.
I have never seen one before and cannot find much info online. Looks like a killer amp. Pricing is an estimate based on similar listings across multiple sites, feel free to make an offer.