The 1 ohm resistor is the shunt and the 1.5k is a series resistor to the meter. A big current went through there for sure. Lucky the plate meter isn't damaged, hopefully it didn't change resistance either. That remains to be seen. Fortunately I've cloned the plate meter in those amps and have them available. My meter only requires changing R7. If someone has a bad multimeter the fix is to switch the meter scale on a good plate meter for the multimeter and then replace the plate meter with mine. As far as your tube, well the filament obviously let go and something happened during the event and it baked those resistors. A quick check of the zener should be done. If that's ok a new tube should get you up and running again.