The first edition of Gamebirds has no printing code. © Copyright 1961 by Golden Press, Inc. Published by Golden Press, Inc., New York, N.Y. No cover price. The number on the spine is 24409. Later editions were priced on the cover.
The only cover (text) change to Gamebirds is shown next. The text on the back cover changed as well. Still dated 1961. Cover price is $1.50. My copy has the letters NOPQR on page 160.
Both of the books shown exist in a large (5 ¼ by 7 ¾ inch) hardcover. The number on the back of the first cover is 63513. No letter code can be found. The second cover has an ISBN number: 0-307-63513-9. Letter code on page 160 is F.
No revised edition exists. Out of print.