Ok I just checked the paper files that I had knocking around for the 3132. My memory has failed me. I have met your exact model of module before. I have a couple of printed pictures showing the difference ! Attached.
The aim of the measurement exercise is to get onto the control voltage line of the 2nd L.O. varicap diodes whilst the covers are on and the module in the chassis. The feedthru that I specified is a DC connection from the varicap diodes to the PLL control voltage driver. I could have chosen a point on the PLL board but that is just making life difficult for no good reason
In the case of the module that did not have the convenient monitoring point where I expected it, I would have carried out DC continuity tests between the varicap diodes common point (between the two diodes) and the feedthru's that emanated from the modules metal shell. One of them would be the control line from the PLL and provide continuity. The blue wired feedthru could well be the right one but you need to prove it.
I have bee thinking about your previous reading of 0V. If you are monitoring the PLL control voltage, it could be that you have a fault shorting the control line to 0V. The fault could be the driver chip on the PLL board or a short to chassis somewhere along the control line. Such a short would still bring the VCO almosyt onto its correct frequency as the nominal control voltage is approx 0V, but the PLL would have lost control of that VCO which can only be bad !
With regard to your crimped solid coax cabled. The copper coax cables are vulnerable to damage and if distorted too badly they can either present a poor impedance match, and standing wave issues, or even a short of the centre conductor to the outer copper screen. The insulation is PTFE which is quite soft and easily crushed to the point of a short, inner conductor to outer. To do so the coax would need to be pretty seriously bent to a right angle though. Minor outer copper sleeve distortion can be tolerated. Much depends upon the signal being carried by the cable and its frequency.
Keep us advised on progress and I will try to help but my repairs were an awful long time ago and the old memory is failing a bit. I am not in a position to dismantle either of my R3132's at the moment so regret direct comparisons are not possible.
Fraser