This is experimental, not fully proven and for discussion only.
The steering on the BSA is Pitman arm, and while some might find this system absolutely fine, I find it twitchy at speed and hard work in tight corners. My arms have got used to power steering and if I lose a little road feel, I can cope with that.
I have been trying various solutions with in - line planetary gears and not having any faith in the results enough to take the idea forwards. Too much lash and, not enough connection options have made me kick that idea into the long grass.
So, try to build a rack.
I saw a video from an American (I think) fellow who has a good deal of skill with metal (1908 rick) Rick Eggers? I think who made a rack from scratch for his kart. I don't have access to high precision tools (eyes can't pop a centre to less than 0.3mm anymore either) so I improvised around his design to allow for poor tolerances with shims. Anyway, here is a short video of it so far.
Comments please.

Jim