cover Union Square Post Office, New York, N.Y., 1c Black on dark green (141L1), huge margins showing bit of next stamp at L., ms. penstroke cancel, used in combination with 3c Dull Red (11), large to immense margins showing bit of next stamp at R., tied by 'New-York Nov 20' c.d.s. on fresh buff cover, extremely fine, a very rare combination usage, with 1990 P.F. certificate, Scott retail $800.00+ (combination usage unlisted) photo