Hi,
I could only get to our Fluke 6kV probe and its manual shows the circuit.
I measured the resistances of it and they agree.
I have also added the manual for the 6kV and the 40kV units
The manuals also give equations for compensation for odd input impedance meters.
Tom.. 
80K-6-instruction.pdf (20.3 KB)
80K-40-instruction.pdf (21.1 KB)