Government of Barbados, watermarked paper as used for the $2 of 1938-49, featuring the heads of a pair of hippocampi, glued into a frame of thick blue card, ink annotations on paper, as produced, slightly larger and more detailed than the $1 watermark, extremely rare, this being one of only two such watermarks in the Portals Archive
BNB B103, Pick 3 £150-£200

These items are directly from the Portals Paper Archive