Expert Builder Series from LEGO (1978)

An ad from 1978 for the Expert Builder Series from LEGO. These new LEGO sets included pistons, gear wheels, and universal joints – movable parts that made models “more realistic and more fun.” The company launched the series with four sets: Auto Chassis, Go-Cart, Tractor, and Sky Copter. Each set came with instructions for building both the model and some related designs.