I'm trying to measure AC on those points now and find it kind of difficult to read. My meter blinks at everything from 170VAC to 30VAC for about a millisecond and then imidiately settles at eighter 1.xVAC or nothing at all.Measure the AC coming out of the rectifier (at the 500V and 250V points) with no tubes installed. If you are only getting a few volts of AC ripple at those points, the chances are that the rectifier diodes and caps are doing what they are supposed to. If you see a bunch of ripple voltage (AC) on top of the DC, then you may have a partial short somewhere in the rectifier system which would continuously draw a lot of current.
I took the measurements with no tubes installed and between point and ground. I also tried between the two points for a similar result.