John McMahon was a painter who worked for de Kooning in the 1960's and 70's! McMahon was the longtime studio assistant of De Kooning... According to de Kooning's biographers, "In the Springs, an important early assistant had been the painter Athos Zacharias, who helped de Kooning establish his initial studio in the garage on Accabonac... But Zacharias would not work full-time, so de Kooning hired John McMahon... for the next twelve years McMahon devoted much of his life to de Kooning... After several years as de Kooning's full-time assistant, McMahon... began looking for another artist to help out."