It occurred to me after I posted this that they advertised "Over a thousand dollars in trophies"...
With one dollar, and fifty cent entry fees?
And look at the list of events...Ah yes, those WERE the days. 
W.
Friends, this should spell out the answer to the question, "where are all the young modelers at?" or "what has happened to control line flying?"
The answer is plain to me.
Sponsorship.
Back in the day, there were many sponsors from many walks of life. And I mean outside the hobby realm. Such as the Navy! car Mfgs. Car dealerships. This of course was encouraged (required?) by the manufacturers. The Y.M.C.A.. Boys clubs, Scouting and more. There were some banks as well. And as you can see by the advertisment shown in the first post, there were lots of prizes for many entrants.
Depending on the event there were also awards of kits and engines. Certainly the LHS helped here and there for these. However, Many of these were not were NOT donated by the LHS. They were purchased by the other sponsors and were usually purchased from the LHS. Also entrant fees were low and in most cases there was no requirement of membership in AMA clubs.
Note also that there would be food provided. I wish i could have attended that event! I wonder if there are many pictures of this surviving.
Considering the local sponsorship, might there be pictures from the local newspaper archive of the event?
This brings into light certain obvious facts. Responsibility mostly. The major responsibility today being insurability of an event like this. This is because back then most people were willing to take care of things themselves. Nowadays if Anything happens we are always looking to see "who's gonna pay for this?" Whether it be a cut on a finger by a prop or a scratch on someones paint job or what about this? A kids model flies OOS? Who would be liable for that? The sponsors for holding the event I suppose...
Also note that there is the Glider event for the kids. What has that got to do with control line? Indirectly of course it helps to open the doors for future advancement in the hobby and of course exposure to a larger happening than just a little HLG contest.
This also encouraged more family participation and in wider age groups.
Please keep in mind this is not a rant, merely an observation of the times. I see the question from time to time and do not usually respond.
Ward, thanks for showing us this nice piece of memorabilia. I bet there are few of these saved from their time. It would be nice to see more of these flyers from the past.
Robert