Yes, it has to do with the thickness. Some early sets came in thinner boxes (depth), while later green boxes are deeper.
Tom
Here is an interesting box I have never seen before. Also, What is Estiblished 1897 referring to? Thanks.
Does anyone know what was the last WWII set that was packaged in the older green K&C boxes? Also was set ws042 in the Green boxes or in the newer wwII photo boxes or did it come in both?