Description:

CHAMBON "ESSAYS": 1937 1/- in deep bright blue BW #145PP(1)B marginal example from the top of the sheet, very well centred, unmounted, Cat $2000. Gorgeous & superb! Derived from the sheet of 50 discovered only in 2013: only two singles have been offered, selling at the Prestige Philately auctions of 7/2/2014 and 2/5/2014 for $1840 and $1495 respectively.

The ACSC ambiguously states "...A sheet of 50 in each colour appeared for sale in Europe". In fact, single sheets of 50 in red and in blue were discovered. The green is exceedingly rare: we have never seen an example but we know that a few exist. The block of 4 in "black" was discovered only in 2014.