[Arran]

I've heard and read that about the value of input filter caps being limited to a certain value, however I am not sure whether that still applies anymore. The reason I say this is that I have run across  values for input filter caps that run across the board, some as low as 30 uf and others as high as 60 uf or more, and this is in factory service literature. Also I'm not certain that this still applies as modern electrolytic capacitors have different construction and different formulas for electrolyte then caps did 50-60+ years ago, they charge faster and have a lower ESR current then vintage caps do, even general purpose caps today do. I'm not suggesting that you ignore the tube manual, or the service folder, but it is something to consider.
Happy Christmas
Arran