[Arran]

Ron;
  How are the voltages reading out of that transformer? I was a bit concerned that the filament voltages may be a little high, I was not sure if you actually needed 3 amps current capacity for the 5 volt rectifier winding, as well as 4 amps would be overkill for the 6.3 volt winding since the rest of the tubes only draw 1.55 amps. Since the high voltage winding was already lower then the original, but at more then double the current rating, it should be pretty close to the 270-0-270 the radio calls for. If any are a little too high some wire wound resistors should take care of it.
It's not really a surprise that it's running cool, but one thing I don't like about the newer Hammond transformers are those plastic labels they glue on them rather then the nice brass badges they used to use, and the nylon washers they used on the bolts holding the end bells on, both are minor and easily undone.
Regards
Arran