With the demise of the A.C. Gilbert company, the Erector brand is now owned by their long-time British competitor, Meccano. It is still sold under the Erector name in the USA. Meccano actually introduced a similar construction set two years before A.C. Gilbert claims to have invented it in 1903. There are a handful of Erector Sets from the 1920s to the 1950s on display in the Miniature Engineering Craftsmanship Museum.
This is Erector Set No. 7-1/2 “Chassis Builder” (original owner, Frank Libuse) from 1927. The set is in its original wooden box with metal tray. It includes fenders, hood and steering front axle to build a white truck.