On your picture you only have the series II selector forks then.. (both with a flat cover).
I compared mine, the shape of the forks is slightly different. So the Dog clutch fits on the series 2 fork, but not on the series 3 fork.
There has to be another dog clutch..
I found this in an internet parts shop:
217522 DOG CLUTCH PTO S1-3 ( OBSOLETE / NLA WHEN OUT OF STOCK)
528331 DOG CLUTCH ( OBSOLETE / NLA WHEN OUT OF STOCK)
Does anyone know what kind of dog clutch the 528331 one is? (there is a 50 euros price difference between both)
Cheers,
Finn