1960 Postage Due Surcharges. 1d on 6½d Maroon, overprint trial, the overprint applied twice in black and once in red, superb unmounted mint, margin at left, very rare and unusual, with B.P.A Certificate (1984) stating "is a genuine printers proof but is of unknown status". S.G. D2 Proof. Photo on Page 142. (Image1)

3d on ½d, Variety overprint double, superb unmounted mint, small "B&K" (Bridger & Kay) guarantee handstamp on reverse. Very scarce, just one sheet of sixty overprinted twice in error. With Ceremuga Certificate (2001). S.G. D3a, £1,100. Photo on Page 188. (Image1)