Here are 3 vintage
ZANE GREY BOOKS
Wild Horse Mesa
Riders of the Purple Sage
Arizona Ames
They appears to be from the 1940's to 1950's
Latest dates mentioned in the books are as follows.
Wild Horse Mesa - 1956
Riders of the Purple Sage - 1940
Arizona Ames - 1930
No dust jackets, light soiling and the odd ding to the covers.
Interiors are very clean