One way to tell for sure is to get under and have a look at the rear diff. The Locker has an electrical actuator on the front side of the diff with a couple of wires coming out of it.

Looks a bit like a small starter motor. The standard diff has no electrics on it so if yours has wires then it’s a locker

the tdv8 didn’t have it as standard, but it was an option. aFAIK only the sc had it as standard upto 09. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

I might have a look next time it’s on a ramp out of interest, I’d doubt it has it but then mine is a bit of a funny spec as it’s a Vogue but has the heated/cooled seats of the Vogue SE so who knows what other boxes got ticked when it was new!!.

This may save you crawling underneath.

"The ElectronicTorque Managed Differential control module uses 3 connectors for all inputs and outputs. It receives a permanent power supply via
a 40A fusible link located in the Battery Junction Box (BJB), and an ignition supply via fuse 24 located in the
Central Junction Box (CJB)."