Having been the Editor of Flying Models magazine for 17 years (but not during the era in which Jack Sheeks was so prolific), I can shed a lot of light on that subject. However, there is the danger of destroying your boyhood visions of what it actually was like in those days at FM. It's akin to looking behind the curtain in the Wizard of Oz...
That was the era spanning the ownership of FM by Rojo Publications (Hal Carstens bought FM from Rojo Publications). The Editor during the "Jack" years was the legendary Don McGovern. Don truly fit the wizard behind the curtain image. He was very creative, but, from what I've heard, was far from the most organized person, or much of a strategic thinker. Don't get me wrong, Don was a great guy, a gifted draftsman and airplane designer (especially seaplanes), and one of the most fun people to be around of that era. He just let deadlines get, well, beyond him at times. Then, like now, it was difficult to find enough good material to fill the pages of the magazine each month. A magazine is a lot like a wood burning stove; it consumes a lot of material each month, and when it's gone, well, it's gone! You have to refill the material bin in order to have something for the next month. And Don would very often find that he was on or nearing a deadline and had little to nothing with which to fill the pages. Enter one Jack Sheeks.
Jack was a designing and building dynamo, and he could literally design, construct, finish and fly a new stunt model in but a few days. Being a motorcycle cop with a family, Jack naturally welcomed the opportunity to supplement his income by selling model designs to a magazine, and without doubt most of his designs went to Flying Models. Don relied on Jack to turn out a model in a pinch on many occasions to meet a deadline. Don would hurriedly ink the pencil drawings that Jack supplied, and would often get the magazine assembled at the eleventh hour for publication just because Jack came through with a new design on order. Needless to say, Don was most appreciative of Jack's willingness to work in that manner, and so Jack got a lot of "ink." It was a very mutually beneficial arrangement!
I once told Jack that one of his published designs probably saved my life - if not my sanity (of course many will argue that I lost the battle of saving my sanity). It was in May of 1968, and I was in Basic Training at Fort Campbell, Kentucky. I was an Army volunteer and as such carried an RA prefix on my service number (draftees had US prefixes). So, I thought I was pretty tough. But a few weeks into training I found myself more than just a bit homesick and even a bit despondent about my prospects of surviving the next few years. I wasn't contemplating anything drastic mind you, but there were many around me who took that fateful step. If they could break under the pressure, I wasn't too sure that I wouldn't also in time.
I went to the PX (Post Exchange for you civilians) to see if the new Flying Models magazine had arrived. It had arrived and in it was a design by Jack Sheeks! That was the issue in which his Freedom 45 was published, and I read and re-read that article over and over for the next few weeks. It most certainly got me through basic training. Jack seemed very pleased to hear that story.
So, we have Don McGovern's habit of being late on deadlines to thank, at least in part, for the plethora of Jack Sheeks stunt designs in FM. And, as Paul Harvey would say, "That's the rest of the story."
Bob Hunt