Dupuis-Maillet is described as a fellow-artist that helped Pfeiffer break into the Montreal artistic community as he moved to Westmount in the mid-Forties.
[7] Dr. Max Stern of the landmark Dominion Gallery of Fine Art (1941–2000) in Montreal was one Pfeiffer's earliest supporters during the phase of his life when he started painting landscapes.
[8] In the Max Stern Collection, a collection of items bequested at Dr. Stern's death to a joint collaborative effort between Concordia University and McGill University is a copy of Pfeiffer's biography and catalogue raisonné entitled Gordon E. Pfeiffer by Cotton Aimers.
[9] Cotton Aimers documents that as Pfeiffer established himself as an artist in the Sixties, large corporations such as Hydro-Québec, Industrial Acceptance Corporation, Kilborn Engineering (now a part of SNC-Lavalin) and Molson Brewery (now Molson-Coors) started acquiring his works for their boardrooms.
Andrew Sidney Dawes purchased ten of his paintings and presented them to McGill University.