Vfsb: Connect a 20k variable resistor between the pin on the left (pin 6) and ground. Decrease resistance to increase voltage.
Check voltage at the MOSFET leg reading 1.35v in post #35

Vmch: Connect a 20k variable resistor between the pin on the right (pin 9) and ground. Decrease resistance to increase voltage.
Check voltage at the leg showing 1.29v on the MOSFET above the LM324 in (post #36)