Stewart
thanks for posting it.
This is a basic schematic. I did not mark some values or tube type because it will change for different parts used.
Look close at a u47 circuit. The LED here is so I can change the heater voltage and keep the bias close to the same. The helper R is something to study.
The multipattern circuit fragment has the best of what I have read and thought about.
This one is not a clone but it is inspired by a number of microphones, U47,U49,E49,U67,VM1. I have tried to take the best of what I learned for this.
I hope this inspires others to try different shape body and maybe circuits that are a little different.