Edward Hagaman Hall printed reproductions of portraits of Mary Philipse Morris (by John Woolaston, and by Copley) and Roger Morris (by Benjamin West) in his Philipse Manor Hall at Yonkers, N.Y. (American Scenic and Historic Preservation Society, 1912), plates X, XI, XII. Where these portraits are today is anyone's guess.
It's worth pointing out that von Erffa and Staley, The Paintings of Benjamin West (Yale, 1986) do credit the portrait of Roger Morris which Hall attributes to West.Eric Homberger