I have seen these on a pre-war BSA and on a pre war tandem. The hubs were made in the early fifties, I believe, so fitted as replacements. They appear to be very robust but also very heavy. If they had come out in the days when people repaired such small components as freewheels, no doubt they would have done well, but the fifties was the beginning of the throwaway age. They were too heavy for lightweights and I don't think anyone specified them as original equipment, did they?
Stuart Tallack in West Sussex