I do not collect ephemera. However, one who would know can be located in the Dealer's Directory in the upper left margin of the main page on this site. Look for Nick Koopman in the SOUTH region and give him a call. He is strictly business, no small talk, but he does know National Geographic.
Also, some of these can be found in "Collector's Guide to the National Geographic Magazine," @ 1971, by Edwin C. Buxbaum.
Thanks for the picture - and good luck!
Appreciate your reply.
LOVE THE RETRIEVERS!
Not sure what information you are looking for. These are all promotional brochures for the NG Magazine. The Greek girls at the Acroolis (1929), the Tower of London beefeaters (1936) and Two Chinese girls in a Moon Gate (1932) are not rare, and can be found periodically on eBay for anywhere from $5 to $20. The Polar Bear Swimming (1919) is much more uncommon and could fetch between $30 to $50, perhaps more.
These promotional brochures and catalogs have been produced by the NGS since 1896 and were sent to members to give to friends and potential subscribers. They were usually folded down the center as your's are. Some versions were targeted at company marketing departments, promoting the NGM as a advertising medium. The NGS would typically mail out anywhere from one to two dozen different brochure of this type each year. They are collectible in their own right. I estimate that from 1896 until 2004 there have been about 1080 such brochures and catalogs produced. In this number I include all forms of promotions, include book announcements.