Here is a Keystone Standard Watch Co. 18 size hunter purchased not long ago...

And here is a closer view of the dial side of the watch...

And here is a photo of the movement number 325756...

A valuable Keystone "Dustproof" * model. These watches evolved from the Lancaster Watch Co. movements. As Lancaster Watch Co. people (and some designs) soon after were producing Hamilton watches. Your very nice (and odd complication) example of that period on the Hamilton "Family Tree" has historical value as well.

* Question, is the mica window equipped cover in this movement. I cannot tell exactly from the picture.

Thanks David, to answer your question yes the mica is indeed intact thankfully...