Hi Stikkan,
It looks like you were sold non matching parts
There are only two different types, pointed tooth or flat top tooth
Either type
pair will work for any year gearbox
It is essential that both parts have the same shape tooth
Some time ago I bought a couple of flat top tooth pinions, However they were not properly made !!!!
The inner bore for the bush was too big
Beware of this if you buy a flat top pinion
Did you buy both parts from the same dealer? If so I would ask for matching parts
John