This is a vintage mono block amplifier from a Baldwin model FF tone cabinet. It has D-520-10H stamped onto the edge of it, with what appears to be a date code of 6411 (November, 1964? 11th week of 1964?). I have no idea if it works. No tubes are included, and I have no way to connect it to anything. I believe this is rated at approximately 30-40 W. The only thing that I know of that needs to be replaced is the fuse holder, which has broken, but is still electrically functional and attached inside the chassis.
It takes the following tubes, according to what is printed on the chassis:
4 ea 6L6 G power tubes
2 ea 5U4 G rectifier tubes
1 ea 6SN7 preamp? tube
17 3/4" long, plus 5/8" mounting flanges on each end
8 3/8" tall
Weight is 33.5 lbs. Lots of heavy iron here.
I'd like to get $140 plus shipping (probably about $45 in the US) for this, but I'm willing to entertain offers. A nearly identical one sold on ebay recently for ~$180.