Ford Mustang Temperature Gauge Sender Question

There was a thread on Corral about the correct temperature gauge sender for our cars, and it led to some confusion.  Here are the facts:

My 96 Mustang EVTM shows a two pin connector (C178) for the ECT sensor for the PCM.  The sender data wire is LG/R (Light Green/Red) and the ground side is GY/R (Gray/Red).  This applies to both 2V and 4V cars.

Here are a couple of pictures of the PCM sender, which, on my car, is on the passenger side of the coolant crossover tube:

The EVTM shows a two pin connector (C137) for the temperature sensor for the coolant temperature gauge in the instrument cluster.  The sender data wire is R/W (Red/White) and the ground side is Y/R (Yellow/Red).  This also applies to both 2V and 4V cars.

However, on my car, I have a single, stud-style connector on my sender with a R/W wire attached to it, and the sender is grounded to the crossover tube.  It does not look like a PO hack job either.   The gauge sender is on the driver's side of the coolant crossover tube.  Here is a picture of it (under the coolant crossiber tube turn on the right side of the picture):

Per the thread on Corral, the correct sender for my car is F7DZ-10884-A, which has a two pin plug, but as far as I can tell, mine is F1SZ-10884-A, which has a single stud-style connector.

I wonder if Ford found the ground to the crossover tube to be bad (maybe due to the crossover tube O-rings?) so they upgraded to a two pin system mid 1996?

Go figure.