found: His Leopold Seyffert, 1952.
found: Portrait of Frederick Paul Keppel, painting, 1929:NNC in-house file (Leopold Gould Seyffert (American, 1887-1956))
found: ULAN, via WWW, viewed August 5, 2014(Seyffert, Leopold Gould (American painter, 1887-1956); variant: Seyffert, Leopold; artist, painter; gender: male)
found: Allgemeines Künstlerlexikon, via WWW, viewed August 5, 2014(Seyffert, Leopold; Thieme-Becker name: Seyffert, Leopold Gould; date of birth: 1888.01.06 or 1887.01.06 in California, Missouri; date of death: 1956.06.13)
found: Wikipedia, August 5, 2014(Leopold Gould Seyffert (January 6, 1887-June 13, 1956) was an American artist. Born in California, Missouri and raised as a child in Colorado and then Pittsburgh, his career brought him eventually to New York, via Philadelphia and Chicago. In New York the dealer Macbeth established him as one of the leading portraitists of the 20th century and his over 500 portraits continue to decorate the galleries, rooms and halls of many of America's museums and institutions.)
