Complex sentence: Price's directional garments attracted a large fan base--especially after Mick Jagger became a customer of Stirling Cooper, wearing Price's button-side trousers on the'Gimme Shelter' tour.
Split into simpler sentences: Price's directional garments attracted a large fan base--especially after Mick Jagger became a customer of Stirling Cooper. He would wear Price's button-side trousers on the'Gimme Shelter' tour.