Complex sentence: Leyland were, by 1954, part owners of SCG but the 1954 PDR1 prototype had the direct air-operated Pneumocyclic transmission at the time, neither Guy nor Daimler had a two-pedal transmission and AEC had only just exhibited theirs on the prototype Routemaster.
Split into simpler sentences: Leyland were, by 1954, part owners of SCG but the 1954 PDR1 prototype had the direct air-operated Pneumocyclic transmission at the time. Neither Guy nor Daimler had a two-pedal transmission and AEC had only just exhibited theirs on the prototype Routemaster.