A good used Jaguar all synchro gearbox reverse gear striking rod, in the manuals it's listed as C21478 (item 32 in the illustration) and fits quite a few models fitted with the all synchro gearbox but obviously check compatibility before committing to purchase.

This came off a MK2 gearbox serial number KCN532 but will fit the S Type, 420, MKX and the E Types that were fitted with all synchro boxes.

The part is used and over 60 years old so does show signs of wear (see pictures) but if yours is broken or damaged and you need a good replacement then this might be for you.