I learned about control line about 1946. My folks use to take us on picnics to Swope Park in Kansas City. They use to have to drag me home. It was love at first sight. It was not until 1950 that I built my first Scientific hollow log powered by what else, but an OK Cub .049. I had received the engine with a Half Pint race car that same year. Does anybody remember those? I built my first gas tank from the sheet of brass they sent, but did not have a soldering gun. I used my wood burning tool and melted plastic to assemble the tank. It worked great and never leaked.
Most of the guys flying in Swope Park were ex military. The war was over, and they were all at the park flying control line. To this day I still believe real control line planes have coils, condensers, and batteries. I have never forgotten the sights and smells. Probably why I have so many ignition engines and planes.