Norton postedThe screws are 2.5mm diameter and 10, 14, and 17mm long. You could probably find hex head screws but they would be wrong. Here is what the prototype looked like.
Pete
Looking at that picture makes me think Torx head pattern,maybe Lionel should have used security Torx heads instead of Phillips. I wonder if they have them in the sizes you have listed and how they would look?
Something like this:
Doug