i have found a box for sale for one of these the only thing is is the middle section that holds the glass does not open with a button like all the others i have seen but instead uses a key to open, has anyone seen one of these?

A key opening box for the Hamilton model 21 was one of the first 330 or so chronometers. Beware of reproductions sold as original. I will say that some of the restorations done recently are considered authentic, such as Gary Selick's collection.

Let me clarify, I have a Gary Selick box for my 267 M21 chronometer. He used the original hardware from the early boxes. He does high quality restorations, and I consider his work equal or better than original. He is the box go-to-man for Hamilton chronometers.