[Elecraft] Need Pinout for Heil HMM "icom" hand mic

[Rick Tavan N6XI]

I need to connect a Heil HMM "for icom only" mic to a K2. The KSB2 and Heil
Website don't mention this mic. The pinout is not the same as the
Heil-manufactured Elecraft MH2. The mic has a handwritten label "PTT 5&6"
and I have confirmed that this is correct. How do I jumper the mic pin block
for audio (pin 1?) and 5V? What value bias resistor should I try?

Thanks,

/Rick N6XI