Does the model you have use a 5879, 12AY7, 12AU7 and a 6X4? The 1952 Gates catalog doesn't have PS details (the 1947 catalog does, but that model uses octals), but it does specify that the unit draws 35W. Assuming the tube compliment above, heaters at 6.3V draw 1.2A = ~7.6W. 35W - 7.6W = 27.4W. B+ isn't specified in the '52 catalog. The octal version in the '47 catalog has B+ at 180V. Assuming your version used 180V, 15mA puts you at about 27.4W. That's assuming you're trying to get close to the original. I don't have a schematic so I can't check that for accuracy.
You'll have more clean headroom at higher B+, and you're not strictly limited by the original power spec as long as all components are adequately rated. You may or may not want to adjust bias on the tubes if you go with higher B+. It's not absolutely necessary, but it all depends on what you're after.
You could get a used or NOS Power One HB200 or HB250 power supply for B+ and a 2A filament transformer and pretty much be off and running if you're not concerned with getting it as close as possible to original operating conditions (assuming original used 180V). HB200 would be close enough to call it original and be done with it.
BT