John Bull, co. 1950, manufactured brake blocks (including rubber and canvas "rain stopper" models in 16 sizes and special ones for alloy rims), handlebar grips (10 different varieties), inflator connections, rubber pedal blocks, reflectors, cycle tyres (10 different models) and motor cycle tyres (two models) and tyre repair outfits.
I am not sure when John Bull ceased production, one assumes in the late 1960s, early 1970s.
By the way, the makers of the old Britannia range of tyres, grips etc. and a keen rival of John Bull, are still very much in business. They are the ones that made my REPRODUCTION (yes clearly stated, thanks very much!) Raleigh roadster grips. They could, of course, make REPRODUCTION Campagnolo brake hoods. But I wouldn't touch that with a barge pole. No sir.
Peter Kohler
Washington DC USA