I made key fobs RF replacements.
https://www.ebay.co.uk/itm/NEW-KEY-FOB- ... SwNU9e21bU
https://www.ebay.co.uk/itm/KEY-FOB-REPL ... 4235180416
Key fob replace:
Works like the genuine key fob 418, the programming procedure in the car is the same as the factory key fob, better range than the factory key fob)
I can also tune (433 to 418, 418 to 433) and repair genuine key fobs made by Jaguar.
I will gladly answer all Your questions.
I also sell door handle repair kits for XJ40:
https://www.ebay.co.uk/itm/164234212535 ... CA:PL:1123