I called it quits for the night before reading up on the other methods of determining what type of differential lives inside the pumpkin.
I did compare it to the rather popular photo of the two different differentials side-by-side, but mine look like neither (at least to me at midnight).
Time is of the essence as I have a trip I must leave for tomorrow in the jeep, so if anyone has any thoughts based on the attached photo, I'd be grateful.
2001 XJ Limited
Towing package (?)
Full size spare (yes)
'01 XJ Limited | "The Red Baron"