@imhififan to the rescue again, thank you!
So Im still trying to understand if/what can be gained from increasing the two Epcos caps? Also can someone please confirm their respective name and role in the amp (some call the input supply, others power supply etc). If I understand their voltage ratings add up and the uF rating in this case is only half of the first caps value, being 11uF correct? This could leave room for a larger rating since the 5AR4 could endure more?
As for the other single large cap, 470uF 500V, what is its role, what can it improve and is this the reservoir cap (any other names for it?) that @noromance suggested could be doubled if it does not impact the choke rating?
Thanks for your patience guys.