Phelon & Moore (P&M) was founded in Cleckheaton, South Yorkshire in 1904. The firm was renowned for its fondness for engines with inclined cylinders, the latter featuring on its new 500cc overhead-valve model of 1923. This was P&M’s first ‘Panther’ and the name would later be extended to the entire range. Post-WW2, Panther added medium-weight 250/350cc models with vertical engines to the range but its largest models retained the inclined engine that had been around seemingly forever and served as the frame’s downtube. A range of Villiers-powered lightweights and a scooter were added in the late 1950s, these and the old long-stroke singles being the only types on offer after 1961. In 1959 an enlarged (to 645cc) Model 120 joined the 594cc Model 100 and the former would be the sole Panther four-stroke in the range after 1963.