So I got my 1ohm 1W 1% tolerance resistors from Digikey a week or so ago and got the amp biased. The calculations I did showed I should have been running ~37mA through the output tubes. Turns out it was running quite hot at 56mA. So things have been tweaked down to the numbers when you calculate using 70% of max for the tubes (25W max the tubes can do, 70% of which is 17.5W; 17.5W / 475V plate voltage gives the magic number 37mA). Now the tubes should last a bit longer than if I'd left it unbiased :).
More pictures to come soon. I'm starting to accrue the tools required to do the head cabinet, and hope to get started by the end of the month.