above is the July 1937 Nat Geo article
the Muhlberg PoW Camp Motoring Club Book called Birds of America that David found in a book shop 15 years ago and paid £3-50 for.
It’s a collection of bound National Geographical mags circa 1936-39 probably sent by the Red Cross.
Thanks David! https://www.facebook.com/Justacarguyblog/inbox/?mailbox_id=672089866306730&selected_item_id=100000465704940
the book made by hand by the POWs was posted in March 2016
and I had no idea they'd worked to put other books together until David mentioned it