Used differential output shaft for flange drive. This design followed the original yoke output shaft on pre-pot joint Minis. Introduced in approximately late 1967 on Cooper S models and ceased when the inner CV "pot" joint was begun. This is the one that is required when Hardy-Spicer drive shaft couplings featuring replaceable u-joints are fitted. New ones are obsolete. This is a good used example. Sold each.
If you don't have all the parts for this conversion, you will need (2) 22A1151 special differential output gears, (2) 22A1104 retaining bolts, (2) 22A1566 oil seals, (4) 88G493 collet half-clips, and (2) 22A1201 thick washers. Many of these parts are obsolete, availability is limited.