It's all clear as muddy water now.
This has made some very interesting research tracing back Ted Halibrand. I know aftermarket parts were rare in the early 60's I can't imagine what it was like after WWII. There was OEM and your imagination, some real pioneers. I'm also saying what to the manufacture of what's called Rudge-Whitworth spline-drives. Being rooted in bicycle wheel manufacture.
Ralphy