Yes, two 68pf´s, one from the backplate to the front, the other from b.plate to the rear.
If you just want to measure the voltages, I think you don´t need this capsule substitution. It makes sense, if you´d like to run the circuit without using a capsule, perhaps for also checking the output etc.
But I would not recommend to use a capsule with 80 volts, if the diaphraghm is getting sucked to the backplate. There might be danger of destroying the capsule if you´re getting a dielectric breakdown...
Perhaps you can change the 2x 470k divider AND change the divider in the psu (3 instead of 2 resistors), so that you´ll get 0v - 60v - 120v - 160v instead 0v - 80v - 160v. But then you´ll need a 8-pin connection between mic and psu for separate connections of the 160 V (plate) and 120V (capsule) voltages. If you´ve got such connectors and a cable with enough leads you can do so.