Titles at the end of the film state that Erector Sets are known in the rest of the world as Meccano Sets, Meccano although very similar is in fact a different product from the UK that pre-dates Erector Sets by a decade. Errector Sets are now in fact made by Meccano.
The USA entered WWI in 1917. In 1918, AC Gilbert goes to Washington to "save Christmas" along with his family, including a 10 year old AC Gilbert Jr. In reality, AC Jr. wasn't born until a year later in 1919.
In a scene set during the 1910s, the "A. C. Gilbert" logo on
the truck door is printed in Aachen Medium, a font that was released in 1977.