1853 3c red on buff, unused cut square, 27x30mm, just clear of indicia at bottom, tiny corner margin crease at top right, otherwise a fine example of this rare Nesbitt die (only one unused entire is recorded) with 2009 PFC, cat. $3750 (Cat No. U6) (Image)

Cat. $3750, Est.US$750

1860 10c green on buff, entire, size 7, knife 20, watermark 1 (UPSS 65), fresh color, small tear on backflap, otherwise v.f., with 2007 PFC, ex-Saddleback. A rare entire (Porter Venn estimates that only 25 exist. UPSS value $4,750) cat. $3250 (Cat No. U33) (Image)

Cat. $3250, Est.US$1,500

1874 3c green, die 58, size 10, knife 54 (UPSS 449), unused entire, with pre-printed "Holden Brothers" return address, backflap partly sealed and the entire opened at top, otherwise v.f. and rare (UPSS catalogue records only four mint non-addressed entires, all with defects), with 2009 PFC, cat. $3500 (Cat No. U168) (Image)

Cat. $3500, Est.US$1,500

1881 3c green on blue, entire, size 10, knife 54, watermark 5 (UPSS 451), cork cancel, with "Burlington, VT Feb 24 1882" cds alongside, addressed to West Royton, MA, with preprinted address at upper left, few insignificant edge tears, otherwise v.f. and rare used entire, approximately 15 exist in addition to a known unused entire, with 2007 PFC, ex-Saddleback (where it brought $4,750 plus buyer's premium) (USPS 451, $7,500) cat. $4250 (Cat No. U170) (Image)

Cat. $4250, Est.US$1,500

1884 2c red on fawn (UPSS 744) cut square, 35x36, used, fresh color, minor paper wrinkles, still v.f., one of the only 3-4 known cut squares (not known in unused condition), with 2003 PSE certificate. A U.S. Postal Stationery Rarity (2006 Siegel Rarity Sale, $18,500 hammer) cat. $25000 (Cat No. U242) (Image)

Cat. $25000, Est.US$10,000

1887 1c blue on oriental buff, cut square, 31x36mm, bright color and sharp impression, v.f. A great rarity, one of only nine believed to exist, with 1991 PFC, cat. $7000 (Cat No. U298) (Image)

Cat. $7000, Est.US$3,500

1900 Patent Reply unused postal card Essay, 1c gray blue and red, some toning, with back label detached, fine (Image)

Est.US$150

1960-70 11c black, pink and violet on white, International Airmail Letter sheet, proposed design for a "Lettergram Priority Mail", with airplane, train and map of the United States indicia, unused with flaps glued in, v.f. and most unusual stationery essay (Undersander EA3C) (Image)

Est.US$500

1960-70 United States Envelope Company, Liberty Bell, 1 4/10c brown on white, large die proof on watermarked stationery paper, indicia printed diagonally in the middle, v.f. and undoubtedly rare (Understander E187A) (Cat No. U548P) (Image)

Est.US$300

1960-70 United States Envelope Company, 6c Whale (Moby Dick) blue large die proof on watermarked stationery paper, indicia printed in the middle, v.f. (Undersander E193Aa) (Cat No. U554P) (Image)

Est.US$250

1960-70 International Envelope Company, entire envelope, with repeating pattern sideways "United States Air Mail Postage 6c" in blue, fully imprinted inside (mirror image) in violet, handstamped "CANCELED" in red, unused, v.f. and most unusual (Undersander EAM8Eb, $800) (Cat No. UC25E) (Image)

Est.US$250

1960-70 International Envelope Co. entire envelope with repeating pattern printed horizontally "United States Air Mail Postage 6c", fully imprinted inside (mirror image) in violet, unused, v.f. (Undersander EAM8E, $750) (Cat No. UC25E) (Image)

Est.US$250

1960-70 International Envelope Company, unused entire envelope, pre-printed horizontally in red "United States Air Mail Postage 6c", double impression, one inverted, fully imprinted inside (mirror image), handstamped "CANCELED" in red, v.f. (Undersander EAM8Db, $800) (Cat No. UC25E) (Image)

Est.US$250

1960-70 International Envelope Company, unused entire envelope, horizontally pre-printed "United States Air Mail Postage 6c" in red, double impression, one inverted, fully imprinted inside (mirror image), v.f. (Undersander EAM8Dc, $750) (Cat No. UC25E) (Image)

Est.US$250

1960-70 International Envelope Company, unused legal size envelope, diagonally pre-printed "United States Air Mail Postage 6c", fully imprinted inside (mirror image) in violet (Cat No. UC25E) (Image)

Est.US$250

1960-70 Air Mail Envelope Essay, 6c unused entire envelope, horizontally imprinted "United States Air Mail Postage 6c" (every other line with inverted wording), fully imprinted inside (mirror image) in red, indicia handstamped "CANCELED", unused, v.f. (Undersander EAM8Ea, $1,500) (Cat No. UC25E) (Image)

Est.US$500

1960-70 6c Airmail envelope Essay, vertically imprinted "United States Air Mail Postage 6c" (every other line with inverted wording), fully imprinted inside (mirror image) in violet, indicia handstamped "Canceled", outside borders omitted (Undersander EAM8Ea, $1,500) (Cat No. UC25E) (Image)

Est.US$500

1960-70 One Cent Revaluation Surcharge, 6c red + 1c green, two entires (one legal size) with red and blue borders, each with Plane Train and Ship surcharge essay without denomination or "U.S. Postage" label, both with black "CANCELED" overprint, v.f. (Cat No. UC30E) (Image)

Est.US$500

1960-70 International Airmail Letter Sheet, 11c red and blue plus 11c blue and red, two essays, each hs "CANCELED" in red, each with shifted globe, v.f. (Undersander EA3Da,b) (Cat No. UC35E) (Image)

Est.US$500

1960-70 2c carmine rose, with 1c green Plane, Train and Ship surcharge essay without denomination or "U.S. Postage" label, overprinted "CANCELED" in black, v.f. and rare (Cat No. UX38E) (Image)

Est.US$500