[Kurt P]

Well finally got back to this and found that I had connected R18 to the negative side of the filter caps instead of the top of R38.  The filter caps are fine, not shorted and I don't see anything else mis-wired in the power supply section.  Still getting a short (some brightness on the dim bulb at 60V but full brightness at 100V and pulling .6A) so it looks that wasn't the only issue...

Is the humbucking coil normally shown in the schematic?  I wonder if this speaker came from a set that needed that coil, while this one (according to service bulletin 146B) doesn't seem to.  Might not be an issue.  I have a clearer schematic now and I can now see that the primary of the OT should be 7100Ω but I'm only measuring 460Ω.  Not sure but that seems way low. 

I can't think of a way to test the power supply without the speaker section since the B+ runs through it.  I'd like to eliminate possibilities of issues in the whole speaker section but other than the resistance readings I don't know of another way to verify it's working.  There's gotta be a basic troubleshooting approach here but I'm missing it, any troubleshooting tips would be appreciated!