Extra stamp on top page block; 1/8" tilt; age-tanning is mild to moderate and uniform.

L. Sprague de Camp's The Hand of Zei. This has a convoluted publishing history: magazine serial was in Astounding October 1950 to January 1951 as "The Hand of Zei." That serial was slightly epanded, and then split into 2 books for book publication in hardcover by Avalon Books in 1962 & 1963 - with the titles The Search for Zei and The Hand of Zei. (The expansion probably consists of a new ending for the first part, and a new beginning for the 2nd part to recapitulate the first part.) For the first paperback edition as an Ace Double, the second "book" was "moderately abridged by the author" (to remove the recapitulation?)

The Search for Zei was re-titled for a British paperback in 1966 (but the second book was not printed in Britain at all.) Decades later, in 1981, the serial was reunited for hardcover publication under the original magzine title (The Hand of Zei) by Owlswick Press. To complete the confusion, Ace reprinted the Owlswick text for its paperback edition, when it was printing the rest of the series. (So the 1982 Ace edition is not exactly a reprint of the 1963 version.)