German Stamp Overprinted Poczka / Gdansk / Polska

Can anyone tell me where this German stamp overprinted Poczka / Gdansk / Polska is located in Scott's Catalog? I cannot find it under Port Gdansk (Polish Offices) or Danzig. Thanks!

Thanks Bayern.

It is not my stamp, I was interested in it on ebay, where is at $5.50 and several bidders.

http://cgi.ebay.com/190552705102

Do you know if similar genuine overprints on other stamps exist with the correct spelling?

BeeSee,

This type of overprint is a dangerous area. For a short time post-WWII, there was a postal free-for-all in Germany. As a result, you tend to see three broad categories of overprints:

(1) official local issues -- these were recognized as valid postage
(2) unofficial local issues -- these were not recognized as valid postage, but some snuck through and can be found used
(3) outright fakes -- these are the most common, and were commonly the result of people overprinting old stamps for philatelic or other reasons

Michel's Specialized lists some of (1) and (2). I suspect this is a (3). There would have been no reason for a Danzig local overprint in 1938/1939, and no reason for a Danzig stamp to have been used in Dusseldorf.

Thanks for the excellent information Postmaster and Bayern