The plate voltage is way to low, even with the tubes unplugged.
If you unplug all the tubes no current should flow and you should measure a voltage close to 300V on all plate connections.
First, re-check all the wires. A photo of your amp-build may be helpful for us to pin-point errors. Also: Check your measuring instrument. Is the battery fresh? Is it a cheap device or something proper?
For further troubleshooting I suggest that you measure the voltage before and after each resistor in the B+ supply path (e.g. in your schematic that would be R28, R22 and R21. That way you can find out where the voltage is dropping and we can make a good guess why that is happening.
Please leave the 220K resistor in place. It's job is to slowly discharge the capacitors if you turn the amp off. They store a lethal amount of energy and having a resistor that discharges the tubes can be a life-saver.
@crasic pointed out the strange connection of the 220k resistor and that it is not connected as a bleeder resistor.
The resistor should be in parallel to the first capacitor. There is clearly an error in the layout here that explains your low plate voltage.
Here is an update of the layout:
Cut the connection from the lower side of the 220k resistor to the + terminal of the capacitor (big cross in magenta). Connect the resistor on this side to ground instead (cyan connection). Connect the upper side of the 220k resistor to the + terminal of the capacitor (magenta connection).
The resistor will now be in parallel to the capacitor and do it's bleeding job and will not be in the B+ supply line anymore.