Through helping an RAC friend look after the 1949 British GP, Gregory quickly became secretary of the 500 Club where he clicked with Moss and his father Alfred, taking on more and more of The Boy’s affairs, arranging Kieft, HWM and Jaguar drives, then buying a Maserati 250F. It was Gregory who got Moss into the Mercedes and later Maserati and Vanwall teams, while also taking on Peter Collins, becoming a director of Brands Hatch, managing the BRSCC and running the Nassau Speed Week, not to mention two flying schools. With Alfred Moss he set up the British Racing Partnership in 1957, providing Cooper F2 and BRM F1 drives for Stirling and other drivers, Gregory doing the deal that for 1960 turned it into Yeoman Credit Racing and brought full sponsorship into Formula 1. He also relaunched an ailing magazine as Cars & Car Conversions, adding publishing to his portfolio, and with Moss Sr opened Britain’s first hamburger joint, claiming invention of the word ‘beefburger’. At the same time he wrote Behind the Scenes of Motor Racing, vividly describing his early years with Moss.
Overseeing his team, as it switched to UDT Laystall and back to BRP, helped Gregory to cope with the aftermath of Moss’s career-ending accident in 1962; although there had been plenty of friction between them, the crash had immense personal impact, and it was Gregory who dealt with the huge press and public demands afterwards.
BRP built its own cars for 1963-64, plus an Indianapolis version, but after being refused FOCA membership it withered financially and Gregory turned to his parallel interest, aviation, building a major air charter service that transported the likes of Sinatra and The Beatles. After his fortune vanished in the 1970s banking crisis, he retired to Spain but retained his incisive mind to the end, updating his book in electronic form in 2012.