I'll second that comment about the timing of Scale Modeler. When they hit the scene, we had two model aircraft magazines in America that were of any use to the plastic modeler.
One was Model Airplanes News, MAN was a flying model magazine, but, had scale plans inside that we could use to make conversions or balsa aircraft with.
The other was American Aircraft Modeler,,,AAM was also a flying model magazine, but, they had a feature called "Scale Techniques for the Plastic Modeler", this feature had things like a one page article about the colors of American bombs (with the correct colors, no less, I just had it out yesterday), to a three page article on building F11Cs and BFCs in plastic.
Our one saving grace back then was anyone that had a hobby shop or a friend that could get Airfix Magazine from England. They did almost all Airfix kits, but, they also did research pieces that could help with your Revell model.
At the same time as Challenge had Scale Modeler, they also had Air Classics,,,,,,those two, plus the mags I talked about above,,,,,,and the Wings and Airpower, kept us in information access until the next Aircam and Profile editions came out. There was a pub from Airfix that I can't remember the name of, but, it featured conversions of Airfix Armour and Trucks in every edition.
1969 wasn't really as big of a "dry spell" for modelers as a lot of people think,,,,,,,,,,I was buying every model magazine and paperback book concerning aircraft (and sometimes tanks), and my $0.95 an hour could hardly keep up, even though the mags had prices like $1.00 (Scale Modeler, December 1967) or 2s 6d on them. (Airfix Magazine, April 1970)
Rex