Okay, still haven't had time to play around, but a quick test of the patterns reveal that there is more volume on the right than the left side both in cardioid and in full omni, capsule seems to be wired correctly as the front is louder than the back... there is however still a lot of sound from the back in cardiod as well... hmmm. Is this the resistors on the dial that need changing as you mentioned before, maybe the psu that needs full recaping too?
More volume from the right compared to the left would indicate the basket/capsule alignment is out ie. the capsule is not facing front/rear or something is interrupting the direct sound reaching one side of the front diaphragm.
Have you had the case top apart? If so you may have misaligned the components on reassembly. If not you need to open it up and check - someone may have had this apart before you. The chassis/basket to capsule alignment
must be correct or your left side will be different to the right and you’ll get spill or reflected sound from the rear. Faulty capacitors or resistors will
not make left different to right in any mode - only front different to rear incorrectly. If the capsule is pointing off axis, or if there is an inner mesh that has solid sides/joints that does not have the solid pointing East/West to the capsule front axis you will get internal reflection off those solid sides (I don’t know if there is a second internal grille basket or not - hard to see from your photos). The solid sides of the housing should line up with the left/right axis of the capsule and with any joins in the pop-filter mesh.
I recently had a mic in for repair and this had an inner mesh that was out of alignment - the join in the mesh was facing the rear instead of being in line with the solid side posts causing Omni and Figure 8 to sound muffled at the rear. Tiny thing that causes huge difference.
Next is voltage checks, first in the PSU and then at the mic end of the cable:
In cardioid the rear element is technically “off” as it should be at the same voltage as the backplate ie. 60V. You need to open up the power supply and check you are getting 60V, 120V and 180V across the 1st, 2nd and 3rd Zeners with respect to ground. Best to measure directly across the pattern switch resistor chain for the first 2 with the switch set in the middle at Cardioid - you should see 60V at the centre pole and 120V at the top of the switch and then check B+ 180V at pin 1 of the cable outlet.
Then check that the voltage climbs with each step of the switch from Omni (0V) through to Cardioid (60V) to Figure 8 (120V) by attaching the “+” meter probe to the wiper of the switch and the “-“ to the bottom (ground). Do this at the PSU - no good checking further down the chain until you know this is correct.
In Omni the rear diaphragm is brought by the pattern switch to identical potential with respect to the backplate as the front diaphragm - they are both now at ground potential - however the rear diaphragm is fed by a high value resistance so you can’t measure this voltage at the diaphragm- only at the switch wiper and then the cable input to the mic - unless your meter is really high impedance in high DC volts range as the diaphragm is fed by a 51MΩ resistance. The backplate is held at 60V by an even higher resistance chain so you can only check your cable continuity and series resistors until you get to the 1GΩ resistor in the mic.
So if all PSU voltages are correct then you need to measure voltages at the cable termination at the mic end. You should get a steady 60V on pin 4 of the cable coming into the mic, you should get your rising voltage from Omni through Figure 8 (0 - 120V) on pin 3 of the cable into the mic. You should get 180V on pin 1.
