The American Philatelic Society Research Library has both the original 1936 edition by Koestler on Alaska first flights plus the 1941 second edition. If this one is listed there it would be in the second edition. They also have copies of two articles written by Koestler on Alaska first flights. Below are the entries from the APS Research Library card catalog which is available on line for members and non-members to use for free
http://catalog.stamplibrary.org/Inm...ie/opac.aspx Note that this on-line card catalog covers not only the very large holdings of the APS, but also the holdings of the 11 other research libraries that hold large numbers of philatelic books and articles. The APS Research Library will either loan books to APS members or they will also photocopy pages out of the books they have for $4.00 for the first page plus 25 cents for each additional page. For example I recently had them photocopy and email to me 20 pages out of the out of print Higgins and Gage Postal Stationery of the World catalog that was last printed in 1986 and the total cost was just $8.75. Keep in mind that the cost includes the time for one of their professional librarians to find the right book and do the photocopying and emailing to you so it is really modest. Alternatively members can visit the library for free in Bellefonte, Pennsylvania if you are ever in the area. Bellefonte is in central Pennsylvania, a few miles up the road from State College which is where Pennsylvania State University is. Having open access to this huge library electronically or in person is one of the reasons why I am a member of the APS.
1. Alaska airmail, a cover catalog / Koestler, August E. -- Portland, Oregon: Western Stamp Collector, [1936]. (Book) HE6238 .K78a 1936 Location: APRL
2. Sourdough flights, second edition of the Koestler Alaska flight cover catalogue / Koestler Alaska flight cover catalogue / (2d ed. --) / Johnson, Jesse G. -- [Norfolk, Va.]: by the
author,, 1941. (Book) G4371 .P8576 J67s 1941 Location: APRL
3. Alaska : Development of its System of Communications / Koestler, A. E., 1944 June. Cover News (Article)
4. Alaska : Emergency Mail Flights from the Islands / Koestler, A. E., 1944 July. Cover News (Article)