Commonly referred to as a 1912 because that is the year it was patented. Pat 1912 is stamped on the bottom of the frame where it attaches to the handle. They use single edge blades.
Yes, it's a 1912. The chain link handle makes it 1927, or later. The bakelite case is also of the same period. These are really great shavers.
For blades look for triple faceted shaving grade blades. The ones sold for scraping just aren't sharp enough.