[OZ4]

For what it's worth

From the high minus voltages on the grids of the 6V6s and the low voltage output of the 5Y3 rectifier. It looks like there is something that is dragging down the power supply. With that much negative bias on the 6V6s they should be going into cutoff and drawing very little current and you should be seeing high voltage on the rectifier output not low.

You should check your I*R voltages around the circuit for something drawing too much current. Something with that 7x7 maybe.

Because of the high minus voltages on the 6V6 grids it tells that there is too much current through the ground off set resistor. It sets up the minus voltages for grid bias. Check it's value. I can't read the part number. It's the one between the center tap of the transformer and the ground point.
 
Something else to keep in mind, todays high impedance voltmeters don't load the circuit as much the old ones did and so you will be getting higher readings than those charts. On the grid readings with the old meters ( 20k ohms per volt ) on the 50 volt scale there would be a load of 1meg on the circuit. ( that is if i am not nuts.) With a grid circuit this will really load things down.


 Good luck