Today I am adding a new picture to the database for the Young Engineers Series (http://henryaltemus.com/series/series34.htm).
The Arizona book is the earlier Format 2 book. As can be seen it does not have the green coloring on the dust jacket cover. Also the earlier Format 2 Dust jackets do not have the little picture on the spine.
In all of the Format 2 juvenile series books the earlier dust jackets never have the little picture on the spine which represents the series.