Herbert David Mullon was born on 1 February 1905 at Marton, the son of Oscar Albert Mullon, a cordial manufacturer, and his wife, Ann Rakaia Haberfield. In 1906 his parents moved to Opunake, where his father bought a cordial-making business. Herb, as he was known, attended schools at Opunake and Puniho. In 1919, after the family moved to New Plymouth, he began working there with the Post and Telegraph Department as a telegraph messenger boy.
By April 1925 Mullon was a cadet at the General Post Office, Wellington. He achieved very high marks in the Public Service Entrance Examination and became a clerk. By 1927 he had transferred back to New Plymouth. Here he began to show a degree of individualism that would see him at odds with management on many occasions during his career. As the owner and ardent student of the rules in the New Zealand Post & Telegraph employees’ handbook , he was regarded by his superiors as a potential troublemaker. He was a member of the Post and Telegraph Employees’ Association and was chairman of the Taranaki section for seven years between 1937 and 1952.
On 5 March 1931, at New Plymouth, Herb Mullon married Grace Elizabeth Avery, an accountant. They were to have four children. As the depression set in, Herb became an outspoken opponent of the salary cuts in the public service. When a petition to Prime Minister G. W. Forbes calling for the government to reverse its decision was circulated in New Plymouth by public servants and a boycott of businesses that did not sign was suggested, he was accused of being a ringleader. Without any evidence being produced against him, he was transferred against his wishes and at his own expense to Palmerston North in 1932.
It was there that he became interested in postage stamps, not for their technical aspects but for the stories behind them. In 1936 Mullon was able to transfer back to New Plymouth, where he called a public meeting and helped to form the Taranaki Philatelic Society. That year the local radio station, 2YB, hired him to give a series of stamp talks. This extracurricular role was not appreciated by the Post and Telegraph Department, but he was allowed to continue as long as his pseudonym, Simon Sam, concealed his identity. The programme ran for 37 years.
During the Second World War, while Mullon served for nearly two years as a postal worker in the signals section at Waiouru, his talks were posted home and read over the air by his wife. When his radio talks were ended Mullon approached the Sunday Express community newspaper and was able to continue as Simon Sam in print. His column appeared every week for 15 more years.
Until his retirement about 1961, he combined this role and his work at the Post and Telegraph Department with his passion for history. His interests included subjects that appeared on New Zealand stamps and New Plymouth’s past, and he published a number of booklets.
Herb Mullon was active in his community. After serving for 25 years on the New Plymouth Public Library and Taranaki Museum committee he received a citizen’s award from the New Plymouth City Council. He was also awarded certificates of appreciation by the Museum board and the New Zealand Broadcasting Corporation. He voiced his views on civic affairs and stood twice for the New Plymouth City Council, without success. He was an honorary life member of the Government Superannuitants’ Association of New Zealand, a Federation of New Zealand Philatelic Societies Award of Honour recipient and secretary-treasurer of the Taranaki regional committee of the National (later New Zealand) Historic Places Trust from 1959 to 1971. In 1988 he was awarded the Queen’s Service Medal. Herbert Mullon died at New Plymouth on 17 September 1991, survived by his wife, Grace, two daughters and two sons.