The orange parts book shows the original part number for the Pantera oil sender to be C9ZZ-9278-A (Mustang). It also show a SW-852 as a replacement part. This is probably a Stewart Warner part.
Below is a pic of the original sending unit from my '71. It measures just under 2" dia at the crimp ring, and 1.55" dia above the crimp ring. The only info on it is "FoMoCo".
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