 Masson was a former Treasurer, Vice President and President of the "Philatelic Society of India" and a frequent contributor to the "Philatelic Journal of India".He was a member of "The Philatelic Society, London", now The Royal Philatelic Society London, and a Fellow of that society from 1899.He formed world class collections of Afghanistan and Kashmir, as well as important collections of Ceylon, Portuguese India, Sirmoor, Poonch and British India.