Mercantile Bank Limited, $500, 26.5.1959, black serial number 4018, blue and black on multicoloured, Mercury at right, watermark of '500' at left, value at all four corners, multicoloured vignetter at bottom centre, reverse light blue, vignette of a 'pai fang' at centre, black serial numbers,(Pick 243, Ma M19), an iconic issue of the issue and also of Hong Kong banknotes, issued only in 1948 and 1959, this is the scarcer date of an already rare issue, a must for the Hong Kong note collector as it is sure to be missing in most collections, about fine