I don't think there's any question that your Hampden New Railway 23-jewel qualified as an American grade railroad watch. It would also likely have been so accepted in Canada by the CPR time inspectors on an ad hoc basis. Enjoy your fantastic find. If you are aware of any provenance, please do share it! If you want to really get into it, I'd suggest that you go to the following forum on the site of the National Association of Watch & Clock Collectors, in which you can participate even as a non-member (but without access to many resources): https://mb.nawcc.org/forums/american-pocket-watches.11/ Respecting the gap between 1902 & 1907, while that could just be due to chance elements, based on my experience there are often gaps in production. This is noted in figures for other watch companies. I'm sure there were various reasons such as the enthusiastic over-producing of new models, downturns in the economy, cut-throat sales tactics by competitors etc.