Hi BlueCrab; thanks again for your input, it is clear to me that you know your stuff! As your entry #275 shows, I still measure 60 VAC. The White Oak mods call for the ctr tap to be connected to the chassis at one point only; the screw formerly holding the terminal strip between the left channel heat sinks. I have just measured the assembled amp again; 60 VAC is on the chassis when the line cord ground N/C.
With reference to the dual 500, did you install a soft start? I ask because I've done a fair amount of research on inrush current on 700's and haven't seen a need for it there. I tend to think the impedance of the transformer limits the current to safe values. Note that the stock rectifier can withstand more than 150 amps.