Hey I've got this steering wheel (SAAS) on my racecar, we bought a boss kit for a 1200 but it was way too long and the steering wheel was up in your face, mainly due to the amount of dish in the wheel. So we machined the guts out of an old stock steering wheel and adapted it with the boss kit that came with the wheel. Something to consider if you get stuck.

excellent idea,i did one years ago,it was dodgy as,might have another go at it if i cant get one. Nice work on your rear wheel arches,i fear i will have to do it to the fatsun,the rears stick out way too much with 14x7s.

does anyone know what other models share the boss for the 1200. I know for sure that a 120Y boss is the same. Would a sunny boss fit? Or others?

sunny310,those early pulsars with the a14s in em have the same steering colum spline,not sure what else tho?

Only three Datsun models used the small diameter steering column shaft, those models being the B10, B110 & B210.
The B10 used blinker canceling pins that were reasonanly close together & this made it unique,
The B110 & B210 share the same specs so the hub/boss is interchangeable between these two models.
All other Datsun models [at least those from the mid 60's], including the B310, used a larger diameter shaft & the boss for any of these will be too big in the hole.