A good used Laycock overdrive sliding member assembly part number 9109 (65814) as fitted to the Jaguar MKX 3.8 it was probably fitted to other British classics fitted with Laycock overdrives but obviously check compatibility before committing to purchase.

Item 67 in the illustration.

Note: there looks to be an 'original sin' chip on the clutch liner (see pictures) but the liner material looks to have plenty of life left in it.