I agree with Mike about the Dana axle break,
(but I cant say for sure about the Salisbury)
I fancy you are in Europe ?
Someone in the classifieds, he is from France was advertising a 3.058 Track loc from an E-type
Power lock diff 3.058 - Classifieds - Jag-lovers Forums
I think that would be a 3.07 ?
anyway, maybe Mike can answer,
but can he just transfer the carrier, crown wheel and pinion and have a 3.07 track-lock ?
…and he is just down the road, not like Ozstralia, where I send parts 3000km
3.07 (open) diffs were stock in Australian spec XJ6, so are fairly common and cheap here