It may be a bit extreme but BSA Twins and Triples and BSA Twins Restoration by Roy Bacon are worth a read. Neither have much general information about the Cyclone, but either will give you some handy info such as paint colours/codes and frame/engine numbers. The Restoration book is particularly handy as it gives carburettor settings, rim/tyre sizes, cam numbers, valve sizes and that more of that sort of info.
I haven't had much to do with unit BSAs unfortunately, but they're a fine bike and I hope you get plenty of enjoyment out of yours.
Regards,
Blue
