Is there a parts cross reference database that will decode the the Jaguar part # from the Item # on a module (or is that even possible). For example - what is the part number for this TPMS module (C2Z1523, C2P20576, ??).

 

Label numbers are engineering part numbers, not orderable part numbers. C2Z is likely the blank module, C2P is probably a programmed variant.
No free decoder exists. You need a VIN lookup on a site like Brit-Car or LRDirect, or a paid TOPIx subscription. What's the VIN?