Dear Peter, Shellwin LF hubs with the angular flanges date from about 1952. Their SF hubs were much more popular. These had normal straight flanges. I had a pair of the LF hubs and I am sure you are correct that they used normal 15/17DB spokes. They were great free running hubs but I can remember a lot of spoke breakages on the gear side. Powell were a much better piece of kit and well worth paying the few shillings extra. Airlights, Baylis Willey, Blumfield, Hardens,Powell and Shellwin would have been the order of poularity amongst clubmen of the early 50's. Normandy and Chater were also about but you hardly ever saw anyone on Chater especially the huge LF ones they made. Kind regards Frank.
Frank Cohen Hoxton UK