Profile Aircraft #113 'The Messerschmitt Bf 109G'
 
The Aircraft in Profile series began its run in 1965 and ended in 1974 and numbered a total of 262 volumes, a respectable run by any measure.  They were printed by Profile Publications Ltd in England and Doubleday in the U.S., another example of collaboration across the pond. 
 
The original format was a 16-page booklet in paper covers with staples, each including several black-and-white photographs and 4 pages of colour profiles.  While these did not hold up well to frequent re-readings or the abuse of a modelling bench, they were both prolific and affordable, a near-ideal targeting of the youthful demographic which was the primary model builders of the time.  The series improved through the run, the artwork grew more refined, and the page count increased first to 20 and later to 24 pages per volume.
 
Soft Cover Booklet
In Fair to Good Condition