A good used original Lucas 141SA 39884 gearbox inhibitor switch, dated Jan 78 and in pretty good used condition, it's been tested and works as it should. Comes with one C16626/3 0.007" shim

This came from a S2 XJ6 but will fit pretty much all the classic Jags but obviously check compatibility before committing to purchase.

You can buy aftermarket reproduction items for about £20 but it's just not the same as an original Lucas specification dated item.