Not available new. Consider second hand part 201712SH or 201712SHASSY which is a pair of constant pinnion shaft and its matching gear 105626SH from the same gearbox. See below.
This part appears on the following Triumph Catalogue Plates
Revington TR information: Consider second hand parts 201712SHASSY which is a pair of constant pinnion shaft and its matching gear 105626SH from the same gearbox. .