There is a whole family of Patent 1912 single edge razors, and they make a great introduction to the world of Gem-style single edge razors: plenty efficient but not too harsh.
The Gem Junior, introduced in 1938, was the last razor to use the Patent 1912 head design. It's a testament to the quality of the design that it stayed in production for so long, albeit under a variety of names. This one is in great shape, with its plating intact, and it comes with a case, instructions, and blades. (We do not recommend actually using vintage blades, as the edges have likely deteriorated.)