That's one version of the "Supreme" circuit, 10" speaker. There were approx. 3 or 4 versions of that circuit over the years, you'll have to go through the tube lineup and match it to one of the schematics. The earliest version had only a volume, no tone, and the last version w/ 6973 output did not utilize a field coil or octal preamp as yours does. By the later 50s octal version they had also done away with the grid cap tube and were 6SQ7 into 6SC7, so your is 1948-1954 or 55 era probably, iirc 6J7 into 6SC7 just off the top of my head? All versions of these are great sounding little amps, they really are.
Oops - had to edit, meant to write 'Supreme' as that's what it is. Model 1600B. I've got a schematic for that one exactly, have to figure out how to post it.