15c Black, F. Grill (98).
Original gum, slightly disturbed with some adherence, choice centering,
sharp impression and clear grill, small perf faults and tiny tear,
otherwise Extremely Fine (Image) 
24c Gray Lilac, F. Grill
(99). Original gum, intense color and proof-like impression, clear and
sharp grill pointsFRESH AND FINE. THE 1868 24-CENT F GRILL IS EXTREMELY RARE IN SOUND ORIGINAL-GUM CONDITION.
Though centered to right, this stamp is arguably Very Fine for the issue. (Image)
24c Gray Lilac, F. Grill
(99). Unused (no gum), rich color, strong grill
impressionEXTREMELY FINE. THE 1868 24-CENT F GRILL IS ONE OF THE MOST CHALLENGING 19TH CENTURY STAMPS TO FIND IN THIS SUPERB UNUSED CONDITION.
With 1992 P.F. certificate (Image)
24c Gray Lilac, F. Grill
(99). Perfectly centered with wide even margins all around, bright
shade and fine impression on brilliant white paper, neat strike of town
datestamp, long and full perforations all aroundEXTREMELY FINE GEM. A SUPERB EXAMPLE OF THE 1868 24-CENT F GRILL. AN EXCEEDINGLY RARE STAMP IN SUCH CONDITION.
The higher-denomination F Grills were produced in limited quantities and are often found either off center or with choppy perforations. This stamp is a true condition rarity.
With 1988 P.F. certificate (Image)
24c Gray Lilac, F. Grill
(99). Fresh color, clear grill, neat strike of quartered cork cancel,
fresh and Very Fine (Image) 
30c Orange, F. Grill
(100). Unused (no gum), extraordinarily choice centering with wide
margins all around, vibrant color and intense impression, bright and
freshEXTREMELY FINE. THE 1868 30-CENT F GRILL IS RARELY FOUND WITH SUCH WIDE MARGINS AND SUPERB CENTERING. THIS STAMP CERTAINLY RANKS AMONG THE FINEST UNUSED EXAMPLES IN EXISTENCE.
The Scott footnote to No. 100 states: "Values for No. 100 are for copies with small margins, especially at sides. Large-margined examples sell for much more." Our best estimate is that no more than a dozen 30c F Grill stamps -- with original gum or unused -- exist with margins and centering comparable to this example. We make that statement after searching auction catalogues for major sales held during the past 50 years.
With 1981 P.F. certificate (Image)
30c Orange, F. Grill
(100). Brilliant color, clear and sharp grill points, bold target
cancel, light corner crease at bottom left, Very Fine appearance (Image)
30c Orange, F. Grill
(100). Light face-free cancel, rich color, clear grill, Fine (Image) 
90c Blue, F. Grill (101).
Unused (no gum), bright color on fresh paper, reperfed at bottom, Very Fine
appearance, rare in unused condition (Image)
90c Blue, F. Grill (101).
Clear grill points, rich color, light diagonal crease, otherwise Very Fine,
with 1985 Brettl certificate (Image)
90c Blue, F. Grill (101).
Remarkably wide margins and almost perfect centering, deep shade and crisp
impression, light cancel, repaired at top left, appears Extremely Fine (Image)