The shop specialised in vintage clothing, movie costumes and old uniforms which were mainly military but the odd policeman's jacket could also be found in there. Popular with what was left of the mod scene in 1966, they also sold pop art clothing such as union jack shirts and frequently advertised in many music and teen mags of the time, welcoming both visitors to their Portobello Road branch and mail order customers. The infamous shop soon became frequented by tourists so a sideline began in postcards and novelty items such as ash trays proudly declaring they had been purchased at Lord Kitchener's Valet in London.

Regular celebrity customers included Eric Clapton, The Beatles, The Who and Jimi Hendrix (who purchased his famous braided military coat there), and it is also said that Peter Blake who designed the Beatles' Sergeant Pepper album sleeve got the idea for the Beatles' outfits whilst wandering past the shop.