1913-34 Seahorses: 1915-18 De La Rue 2s.6d. marginal watermark inverted showing “E” of “POSTAGE”, fine lightly mounted mint. S.G. N64ya. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. pale sepia brown, superb unmounted mint example from the top-right corner of the sheet. Brandon certificate (2018). S.G. Spec. N64(1). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. pale sepia brown, very fine unmounted mint from the foot of the sheet. Brandon certificate (2018). S.G. Spec. N61(1). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. chrome (very pale sepia-brown), a superb unmounted mint lower right corner marginal example of this rare and highly distinctive shade. Brandon certificate (2016). S.G. Spec. N64(2). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. yellow-brown in a fine unmounted mint pair from the top-left corner of the sheet. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. yellow-brown with watermark inverted, fine unmounted mint from the right of the sheet, very fresh appearance. R.P.S. certificate (1989). S.G. Spec. N64f. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. bright yellow-brown, mint, some gum stains at top, otherwise fine. R.P.S. certificate (1983). S.G. Spec. N64(8), cat. £375. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. cinnamon-brown, very fine unmounted mint. Brandon certificate (2022). S.G. Spec. N64(9), cat. £3,250. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. cinnamon-brown, very fine unmounted mint. Brandon certificate (2017). S.G. Spec. N64(9), cat. £3,250. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. deep brown, fine mint. S.G. Spec. N64 var. Hendon certificate (2022). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. seal-brown corner marginal pair with upper stamp watermark inverted and lower stamp showing “E” of “POSTAGE”, fine unmounted mint. Brandon certificate (2006). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. very deep brown with watermark inverted in an unmounted mint block of four from the right of the sheet, very rare watermark variety. S.G. Spec. N64(11)f. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. very deep brown, a superb used horizontal strip of three, very rare. Brandon certificate (2015). S.G. Spec. N64(11). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. reddish brown (chestnut), fine unmounted mint. Brandon certificate (2016). S.G. Spec. N64(12). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 2s.6d. blackish brown, a superb unmounted mint vertical pair from the lower-right corner of the sheet, very rare. Brandon certificate (2015). S.G. Spec. N64(14). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 5s. pale carmine with inverted watermark, a superb unmounted mint pair from the upper left corner of the sheet, rare. S.G. Spec. N47b. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 5s. pale carmine corner marginal horizontal pair unmounted mint, with centre sheet marking in margin, fine and well-centred. S.G. 410, cat. £2,800+. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 5s. bright carmine, unmounted mint, fine. S.G. Spec. N67(1). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 5s. pale carmine (worn plate) used block of ten (2 x 5) with rubber London Foreign Section Apr. 26 1918 c.d.s’s, scarce multiple. S.G. 410, cat. £5,000+. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 5s. bright carmine handstamped “SPECIMEN” in violet, without gum, fine. Brandon certificate (2009). Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 10s. blue (deep shade), fine unmounted mint. S.G. 412, cat. £4,000. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 10s. deep blue, unmounted mint and well-centred, fine. S.G. 411, cat. £4,250. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 10s. deep blue used block of ten (2 x 5), London “9 OCT 18” rubber datestamps, mainly very fine and well-centred, a scarce multiple. Cat. £10,000+. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 10s. deep blue, used block of six (2 x 3) with Sept. 10 1918 London Foreign Section rubber datestamps, scarce multiple. Cat. £6,000+. Photo. (Image1)

1913-34 Seahorses: 1915-18 De La Rue 10s. bright (‘Cambridge’) blue, very fine unmounted mint. Brandon certificate (2022). S.G. Spec. N70(3), cat. R12,000. Photo. (Image1)