Oswald Marsh (26 October 1880 – 4 August 1951)"Oswald Marsh - Philatelist Extraordinaire" by Michael Peach in Gibbons Stamp Monthly, July 2009, pp.45-48. was a London stamp dealer who specialised in cut-outs. Many Marsh covers have addresses created using addressograph plates. Oswald Marsh was not related to Victor Marsh.
