Tight and square with flat spine; 1" fold-trace at bottom right corner; light wear to back cover. (This may be unread, with some shelfwear.)

When I started reading and collecting Heinlein, this is what they looked like, and even after I got them in hardcover - the early Signet paperbacks remain the standard of how I think a Heinlein book should look.

The Green Hills of Earth: the second volume in Heinlein's "Future History" series.

(Timeline)
Delilah and the Space Rigger
Space Jockey
The Long Watch
Gentlemen, Be Seated
The Black Pits of Luna
It's Great to Be Back
"-We Also Walk Dogs"
Ordeal in Space
The Green Hills of Earth
Logic of Empire

Most of these originally appeared from 1947-49 in non-SF "slick" magzines like Saturday Evening Post, American Legion, Town & Country, or Argosy - with only 2 from Astounding in 1941.