Hi Norm.

We don't have much information on these either, but yours do show a lot of similarities with this one on OTD:

My guess is that that one has had the Heuer shield added, as it's in a form associated with several decades later and that the dial would originally have had no maker's name, like your example. These silver-cased pocket watches are essentially hand-made, so it's quite natural that there will be detail differences between them.

I'd say you have the right decade with WWI but I couldn't narrow it down any more.