2c Black, 3c Rose (65, 73).
Both stamps tied by bold strikes of Honeycomb fancy cancel (New York
foreign mail type), red "New-York Br. Pkt. Dec. 5" circular datestamp on
1865 folded letter to Cadiz, Spain, red "8.R" due handstamp, London
and Cadiz backstamps, file fold clear of stamps, Very Fine, an extremely
rare example of the 2c Black Jack paying part of the 5c British Open Mail
rate to Spain, probably no more than six such covers extant (Image) 
2c Black (73). Two singles,
used with 3c Rose (65) and 10c Yellow Green (68), two of each,
cancelled or tied by cogwheels, "San Francisco Cal. Jan. 30" double-circle
datestamp on cover to Dordogne, France, red "New York Paid 12"
credit datestamp, French transits including small boxed "P.D." tying one
stamp, 1866 receiving backstamp, Very Fine, an attractive three-color
franking paying the double 15c treaty rate to France, ex Klein (Image) 
2c Black (73). Used with
3c Rose (65) and four 10c Yellow Green (68), tied by targets and
"Stratham N.H. Nov. 4" circular datestamp on yellow cover to Swatow,
China, red "Boston Br. Pkt. 40 Nov. 8" credit datestamp with month slug
inverted, 1864 London transit, sender's routing "Overland via
Southampton", Hong Kong backstamp of Jan. 25, 1865, cover barely
reduced at right, Very Fine, an attractive three-color franking paying the
45-cent British Mail rate to China via Southampton, ex Gehrmann and Haas.
(Image)
15c Black (77). Intense
shade and impression, cancelled by deep green "Cheyenne Dak." circular
datestamp, trivial corner crease at top right, otherwise Very Fine, the
15c 1866 is exceedingly rare with a true green cancellation -- we have
never seen another example with this Cheyenne, Dakota, datestamp (Image)
24c Blackish Violet (78c).
Original gum, incredibly deep rich color and proof-like impression, s.e. at
right, few toned perf tips at leftA FINE AND EXCEEDINGLY RARE ORIGINAL-GUM EXAMPLE OF THE 24-CENT BLACKISH VIOLET. THIS IS THE ONE OF THE RAREST STAMPS OF THE 1861-66 ISSUE, ESPECIALLY IN ORIGINAL-GUM CONDITION.
The number of 24c Blackish Violet stamps with original gum known to us can be counted on one hand. Notable examples are the Caspary/Lilly stamp and the Wunderlich/Zoellner copy, which realized $40,000 hammer in our 1998 auction.
With 2001 P.F. certificate (Image)
24c Blackish Violet (78c).
Deep rich color in the unmistakable Blackish Violet color on thick paper,
sharp proof-like impression showing every detail of the engraving, framed
by an enormous border of white margin on all four sides, clear strike of
Star in Circle fancy cancel (probably a New York Foreign Mail
cancel)EXTREMELY FINE GEM. THE 24-CENT BLACKISH VIOLET IS THE MOST DIFFICULT STAMP OF THE 1861-66 SERIES TO OBTAIN -- EITHER UNUSED OR USED -- IN SOUND AND CENTERED CONDITION. WITHOUT QUESTION THIS IS THE FINEST USED EXAMPLE OF THE 24-CENT BLACKISH VIOLET IN EXISTENCE. A REMARKABLE STAMP IN TERMS OF COLOR, IMPRESSION, CENTERING AND CANCELLATION.
A thorough search through past auction catalogues will demonstrate how rare this stamp is in either used or unused condition. With regard to used stamps, this shade was lacking from the Ishikawa, Grunin, Klein, Caspary and Twigg-Smith collections. The Zoellner collection contained an original-gum single even though the rest of the series was obtained in used condition, because a suitable used stamp was never offered. The Dr. Morris collection contained a used example with considerably smaller margins than the stamp offered here.
An examination of the frequency with which other scarce used stamps from the 1861-66 Issue appear at auction demonstrates how undervalued this stamp is in the Scott Catalogue. The Blackish Violet is considerably rarer than the 3c 1861 Pigeon Blood Pink, which catalogues $3,500.00 in used condition.
The catalogue value for Scott 78c did not change between 1996 and 2001. It has only increased by $250 in the recently released 2002 Part I catalogue, probably in response to prices for other stamps of the 1861-66 Issue.
With 1994 P.F. certificate (Image)