1956 Wildings 1 1/2d green mint nh, imperforate imprimatur pair from the foot of the sheet ex delivery coils, the reverse with "BPMA" handstamp, fine and scarce. (Image)

1857-72 Dollis Hill trials; 2d red-brown imperf. vertical strip of three on handmade paper with green phosphor in the pulp, vertical tear as this paper was susceptible to tearing as it was printed on very thin paper, without watermark, affixed on cover address to the P.O. Research Station at Dollis Hill tied by Sheffield 18 DEC 1971 machine cancel (S.G. Spec. ST5 (2)a). (Image)

1957-72 Dollis Hill trials; 2d red-brown with green phosphor in the pulp, part sheet with portions of 11 imperf stamps, the reverse with annotation made by C. F. Forster who was in the laboratories at Dorris Hill, caused by it slipping on the roll during printing and being partly obscured by another trial piece (S.G. Spec ST5 (2)a), ex Klempka (author of "The Dollis Hill Find", illustrated p.14). (Image)

1957-72 Dollis Hill trials, 2d red-brown, wmk multi Crowns to the right, with green all-over phosphor in strip of seven with only the top halves of the stamps printed and cancelled by Middlesex 29 FE 1972 cds. This was caused when the fragile handmade paper used for part of the trials had torn and was repaired during the printing process with tape which was then printed on. This tape has become detached leaving only the top halves of the stamps printed. The strip shows machine cuts to the top, bottom and left hand margins giving the impression of having been dispensed through an automatic affixing machine. Ex Edward Klempa, author of "The Dollis Hill Find" (illustrated on p.24). (Image)

1959 Wildings 3d deep violet "Dollis Hill Phosphor Trial" perforated block of four on gummed crowns wmk (sideways left) paper, with one 4mm blue phosphor left side band printed over the ink, very fine and scarce (S.G. Spec ST7(3)f). (Image)

1964 20th International Geographical conference set of four imperforate imprimaturs with "NPM IMPRIMATUR" handstamp on reverse, mint n.h., very rare, one of 10 sets released for the NPM archive sales. (Image)

1964 20th International Geographical conference set of four imperforate imprimaturs with "NPM IMPRIMATUR" handstamp on reverse, mint n.h., very rare, one of 10 sets released for the NPM archive sales. (Image)

1964 Geographical Congress 8d mint n.h. with inverted watermark, very fine and scarce variety (S.G. £2'200). (Image)

1966 British Birds (phosphor) mint n.h. se-tenant block of four with variety bistre omitted affecting all four stamps, top right corner marginal, offered with a normal for comparison, very rare so fine, especially without the usual gum toning (S.G. £6'000+). (Image)

1966 Battle of Hastings 1s3d mint n.h. lower left marginal cylinder block of 8 showing progressive gold omitted (Queen's head) with two complete omissions and two partial omissions in the left column, with the cylinder number for gold still present, very fine and rare (Note: Although not listed by S.G. due to the possibility of the gold being removed chemically, the fact that this block shows a progression of the omission proves that this is a genuine error). (Image)

1967-70 1s pale bluish-violet mint n.h. block of 24, Cylinder 11, No Dot Head Type C, Gum Arabic 2B, 6 rows affected by a vertical comb jump, perf F(L), scarce. (Image)

1968 British Bridges set of four imperforate imprimaturs from the right of the sheet, mint n.h., each with "BPMA" handstamp on reverse, very fine and scarce. (Image)

1969 British Ships 5d mint n.h. with variety black omitted (hull, Queen's head, face value and inscription), a pristine and spectacular modern error, incl. normal for comparison (S.G. £2'750). (Image)

1970 Literary Anniversaries 1s6d Grasmere mint n.h. imperforate imprimatur, the reverse stamped "N P/ IMPRIMATUR" in black, rare. (Image)

1971 Literary Anniversaries 5p, variety gold omitted, mint NH, very fine and rare with only 36 known. (Image)

1971-93 Scotland 5 1/2p violet mint n.h. imperf. vertical pair from the foot of the sheet, very fine. (Image)

1972 BBC 9p with brownish slate omitted (Queen's head) tied to Post Office FDC by Gloucestershire FDI cancel, ms address, very fine and unique example on FDC, cert. Brandon (1997). (Image)

1973 European Communities set of three imperf. imprimaturs from the right of the sheet (the 5p in se-tenant pair), mint n.h., each with "BPMA" handstamps on reverse, very fine and scarce. (Image)

1973 British Explorers 5p with variety black-grey omitted (Sir Francis Drake’s jacket), mint n.h. right marginal, very fine and scarce (Pierron records only 24 mint examples), incl. normal for comparison, cert. Brandon (1997) (SG £2'250) (Image)

1973 9p Explorers, variety Gold Omitted, mint n.h. Rare with only 100 known. (Image)

1973 British Paintings set of four mint n.h. imperforate imprimaturs from the foot of the sheet, each with "BPMA" handstamp on reverse, very fine and scarce. (Image)

1973 Paintings 5p with GREENISH YELLOW OMITTED variety, mint n.h., very fine and scarce, Pierron records only 30 mint examples of this modern error, incl. normal for comparison (SG £1'200). (Image)

1973 Inigo Jones set of mint n.h. se-tenant pairs with variety phosphor omitted (shows as a white background rather than a cream background), offered with normals for comparison (S.G. Spec. W225/6b). (Image)

1974 Winston Churchill 5 1/2p imperf. imprimatur in mint n.h. traffic light corner block of four, each with "BPMA" handstamp on reverse, very fine and scarce. (Image)

1977 8 1/2p Tennis irregular traffic light block of four, the lower row of three with blind perfs at base, mint n.h., scarce. (Image)