Marson's final Paralympic Games came in 1976 in Toronto, Canada. He failed to win medals in either of his athletic events or the individual wheelchair fencing events, but did take a bronze medal in the men's team épée. He was President of Federazione Italiana Sport Handicappati from 1980 until 1990. He died in 2011 and in 2012 he was inducted into the International Paralympian Hall of Fame. On 14 May 2021, Jovian asteroid 39795 Marson, discovered by astronomers at Spacewatch in 1997, was in his memory.