I don’t know if others have said this here before, but at a glance I didn’t notice any mention of it: you do not require a working prototype in order to apply for a US patent. An idea is enough, and a patent lawyer could help you write the application.

If you’re fairly confident that the idea is patent worthy, you should consider getting started on an application for a patent right away.

…on Daniel Craig’s wrist.

I was robbed in a bar in Helsinki in 2013. They made me pay 9 EUR for a mediocre lager.

EDIT: watch looks great, IMO!