The steering column had the correct end welded onto it and it fitted a treat (benefit of hindsight – no it doesn’t). It does sit a little close to the inlet manifold support bracket so I’ll either fab up a new one or grind a bit out of it. But, the point of going through the hassle of keeping a splined end – I could use the standard Mazda seal:

I also fitted the inside one, though it will be removed if I end up kicking it in the footwell

And… we’re still towards the end of March and my dash arrived!