Z3 steering wheel boss - airbag

[Welshkiwi]

Hey guys,
Really struggling over in NZ to get a steering wheel boss to fit my Nardi steering wheel that I have bought.
Tried a generic E36 boss today and it wouldn’t fit, wouldn’t fit the splines on the shaft.
Some info suggests that it could be an E39 fitment because it has an airbag? Is the shaft a different size?
I have found from other feeds that people have fitted OMP STEERING WHEEL HUB BOSS KIT fits BMW Z3 95-02 [OD/1960BM545A]

This of course will need a pcd spacer for the Nardi fitment, but that is no issue.
So I suppose the question is for a 1999 z3 2.8 with an Msport airbag wheel (dual stage?) set up anyone know what I can fit?

I am looking to keep horn usage and steering lock action with whatever I fit. Going to fit a Farina symbol or Nardi Torino horn button assy in the centre.

Any advice is really appreciated, I have spent more hours researching this now this week than working on the car! I bow to your knowledge.....