An extremely rare and striking Arab Republic Yemen Currency Board partial banknote progressive die proof engraver's test strike for the obverse of a five rials note, issued circa 1973, in deep red with depiction of the buildings of Wadi Du'an to far left side, values to corners, ink bleeding to fields, on paper/card with virtually four plate margins, together with two die proof engraver's test strike partial vignettes of the buildings of Wadi Du'an, on part-cut and part-torn paper/card (all extremely fine). Provenance: from the personal archive of the late Alan Dow, master banknote engraver to Bradbury Wilkinson & Co and the Bank of England.