I have read carefully. One issue here is my assumption that a wire to the body is a ground. I stand corrected. My thinking there is based in larger assemblies where wires to a chassis are typically a ground: mea culpa.
Regardless of my error in terminology, I received 3 TSC-2 cartridges that each have 2 white wires connected to them: one to the center of each face. There is no Blue wire beyond the additional wires supplied (Which is apparently polarization and can be connected through the mounting screw as I have done, but you seem to prefer a direct connection with a shorter screw). The latest image you've posted again shows a cartridge with different colored wire to each face and a 3rd wire to the BP.
So then the only connections are the white wire of the face I decide to use (SGNL) and the BP (POL) which would be the blue wire: in cardioid configuration the the rear face remains unconnected, or connected to GND.
Is that correct?
eso