The North American Watch Co. (NAWCo), having obtained the factory of the Bell Watch Case Co. of Mansfield, Ohio, manufactured watch cases and were dealers in watch cases and complete watches (the movements being made by other companies). According to a 1902 Ad in the The Jewelers' Circular - Weekly and Horological Review, the company was incorporated in 1902. The company stayed in business at least as late as 1925 since they were still advertising in The Conductor, the journal of the Order of Railway Conductors. You can view a May 1925 ad, showing one of their very distinctive-looking mid-1920s era cases at the Elgin Watch Collectors Site. Also online are similar ads from September 1925 and November 1925. A search can be done by left clicking on the “Search” button at the top of the thread and then choosing “Advanced Search” to open a page that lets you specify keywords, forums, dates and authors. If you use “NAWCo as a keyword, you should find a few threads on the North American Watch Co. and its cases.