While working with these images of Stevenson's work, I began to notice some patterns and similiarities in the material.  A few things that stand out in his work to me are:  his use of bold colors, simplicity of composition, attention to detail, and repeating elements in different and creative ways. 

To the point, while sizing this last cover, I noticed one of the lads in the center of the circle and it seemed as if I had seen him before.  So I selected a couple of subjects and arrived with the composite posted below.  To my simple mind, the young guy in the first poster in this thread and the combat participant  have more than a little resemblance.

Air Progress   -   Fall 1959

For the fall 1959 issue of Air Progress, Howard paints the Wright brothers at Kitty Hawk.

American Modeler   -   January 1959

In this cover, Howard paints Albatros D-IIIs escorting Friedrichshafen G-III bombers on a night bombing mission.

Flying Models  -  September 1957

This is the last cover for Flying Models by Harold that we could find.  Nor are we able to find any more articles or plans  in FM by him after this date.  It shows a contestant on his way to the Nationals by hitchhiking.  Quite a different way than illustrated on the cover in message #9 at:
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl?num=1468046845/16

The original artwork of the July 1957 was awarded to Stuart Babcock, president of Babcock Models Inc.

Flying Models   -   June 1957

Another contest scene by Harold depicting a UC carrier event.  For a second time he merges two images into the same painting.  This time a 'ghosr' aircraft carrier becomes part of the cloud background of the contest scene.

Flying Models  -  April 1957

This cover showing the release of a jet powered F4D for flight, once again illustrates Harold's simplicity and attention to detail coupled with a striking use of bold colors.