Moe is a big part of Rob Fitts' book "
Banzai Babe Ruth" which came out a few years ago. It focuses on the 1934 tour of Japan (where Berg took the movies of the Tokyo skyline later used by the USAAF in identifying targets). Besides the Berg parts, Fitts' book is a great glimpse of 1934 baseball, a must have if you collect Goudey and Diamond Stars and love the story behind the players - Lefty Gomes, Ruth, Gehrig, Mack, Foxx - they're all in there and the author brings them all to life. There's a great look into the Ruth-Gehrig relationship and I really enjoyed how The Babe was portrayed in the book. Plus there's an additional sub-plot of a military coup and how the US baseball tour played a part in it. Reads like fiction, but it's all true - but anyway, its a contemporary book about Berg besides the usual "Catcher was a Spy" that's often read.