Analysis of information sources in references of the Wikipedia article "Weyhe Gallery" in English language version.
A 2017 book by researcher Lynn Rother titled Art for Credit, about the role of art used as loan collateral during World War II, states that there is no evidence that the Chagall was seized under duress, and that it was negotiated willingly by Matthiesen's gallery.
the work was in the possession of Flechtheim's niece, Rosi Hulisch—who committed suicide before she was to be shipped to a concentration camp—when it was acquired by Kurt Feldhäusser, a member of the Nazi party, in 1938. After Feldhäusser was killed in Germany in 1945, his art collection was left to his mother, who consigned it to the Weyhe Gallery in New York a few years later. Morton D. May of St. Louis, Missouri, purchased Artillerymen in 1952 and donated it to the Museum of Modern Art in New York in 1956. In 1988, the painting was transferred by MoMA to the Solomon R. Guggenheim Foundation in exchange for other works.