While working on a Corinphila Auction (April 2006), I was lucky enough to locate and later certify, the attached Postal Stationery card with two fine strikes of this rare mark. The late Meiso Mizuhara’s book showed, on page 18 in Postal History of Korea his recorded dates of use of this rare cancellation: May 20, 1889, until July 30, 1891.
His single example is illustrated, and he recorded just one further strike known on a cover. Mizuhara’s illustration showed a Japan 3 sen UPU postal stationery card cancelled with two strikes of the “CENZAN*POST” date stamp for 27 October 1889, mailed via Shanghai and Hong Kong to Hamburg. The card illustrated in Figure 1 is from the same series, being the Japan 2 sen UPU postal stationery card used with a Koban issue 1 sen green for the overseas UPU rate of 3 sen. There are three strikes of the “CENZAN*POST” date stamp in black dated August 12, 1889. The card was written in German from Gensan, sent via Nagasaki addressed to a German Steamship at Kiel (arrived September 28).
(Originally from KP Vol. 50 No. 4 (November 2005), reprinted here for the philatelic information the text holds.)