 Munn became the managing director of London jewellers Wartski, where he had worked since the age of 19; his specialisation is jewellery, especially that of Fortunato Pio Castellani, Carlo Giuliano and Peter Carl Fabergé.Wartski are jewellers by appointment to HM the Queen and HRH Prince of Wales.The firm made the Welsh gold wedding rings for the Prince of Wales and Camilla Parker Bowles, and Catherine Middleton when she married Prince William in 2011.