Another military personnel set that I recently acquired is the 603 Army Personnel-Private (seated). A few months earlier, I had purchased a similar set, but had not noticed that the soldiers were made of plastic and not metal. I was somewhat disappointed, as though they looked quite good, they were so light that it was difficult for them to stay in place. Recently, another set became available, and it was for sure the metal version, so I bought it. This also appears to be mint and never used or even removed from their sitting place in the box. After checking, I determined that this set was not introduced until 1957, and my box lid does show a 1957 date. All in all, Dinky did a nice job with these soldiers. Not as detailed as the various pre-war versions, they still add quite a bit to the military pieces in a collection.
You are showing the original box for 12 figures and in my experience this box always contained metal figures.
My two boxes are shown below, the one like yours and the newer, smaller, box which I have always found to contain the later plastic figures.
Dave--You are quite right, the diecast figures were in the larger box, and I assume always were. The plastic figures I had bought earlier did come in the smaller box, enclosed in a small clear plastic bag....all lumped together. As I mentioned, the plastic figures actually look pretty good, but they are so light that they very easily move or fall out of place. I had 10 of them seated in the rear of my 151 Military Transport, and whenever I picked it up or moved it, they would fall over. I think that would have been very frustrating for young boys to try and play with them.