Great Britain 1855 1d red brown Plate 25, SG29aGreat Britain 1855 1d red brown Plate 25, (Neal's Steam Press Experimental Printing) SG29a. A very fine and fresh unused imperforate block of four lettered 'GK HL'. A lovely multiple without any of the usual heavy creasing as normally seen on this failed experimental printing. Very rare as only a half sheet of imperforate stamps from the different shade of plate 25 exist, with most being in poor condition. GP Specialised Catalogue No: C8(1)h.