Introduced in 1913 by A.C. Gilbert, Erector sets allowed children to build working models of everything from bridges to locomotives using metal beams, gears, and motors. Dubbed “the toy that builds ...

Editor's note: This story was originally published in 2017. How many times have you said, “If I had only kept my old toys, I’d be sitting on a gold mine today”? The catch is you would have needed to ...