Genuine Laygear for Pre A plus mini including 1100/1300 except "S" & 1275GT 4 synchro gearbox. Nearly always stamped with part number on.

The later type laygear has the same teeth count 15/20/25/29 usually mated with the later type mainshaft with 18mm nose for 1st motion shaft.

Later type laygear is DAM3169-which takes larger bearings and will also need later type 3 step layshaft and correct end float shims.