Dating Gem razors can be dificult because unlike Gellette there are no date codes on them. While there are ranges of production dates associated with the various models, even these are approximate because there are no records. Often the only way to give an approximate date is by looking at old advertisements in magazines.
That being said, since you have the original box and blades I would say that your razor was made towards the end of the 1912 style production. It has a more modern look and feel to it than the earlier models had. The thin bakelite handle, and the style of cardboard box, and the style of razor blade box, are not as fancy as the earlier models. I would say late 1920's or even early 1930's. The Gem Micromatic came out about 1930 and spelled the end of the 1912 stlye of razor. It is hard to say exactly when gem stopped making the 1912 style razor. Did the stop when the Micromatic came out, or did they continue for a while?
Perhaps Hoosier Trooper or someone else has seen an old advertisement for this style that can give a better evaluation.
Thank you for the insight. I did not realize it could be that old! I also saw Juniors with fat Bakelite and metal handles in the same box. There is The Parade on the box. I do not know if that name says something date-wise. I also saw the same razor in a different box.
I agree with UncleScott, that's probably a later model one. Here's a page from a merchants catalog from 1947 or '48, note the Gem at the bottom of the left column. It's in the same box as yours and describes it as having a plastic handle, even though the one in the illustration appears to have a metal handle. Whether they were still actually making the 1912 well into the 40's or this was leftover stock they were selling we'll probably never know for sure, but my guess is they were still making them even after the Micromatics were into their third version, the Flying Wing that is at the top of the page.
Well, it came in a nice box with three sealed Micromatic blades. The razor has never been touched. Nice patina, no rust whatsoever. Even the blades look brand new. Amazing. Polished it and put one of the original blades in. Looks nice, but is shaving with that 60 years old blade a suicide?
"GEM's exclusive bevel-head brings the blade in contact with the beard at root level and compels you to shave with the long, sweeping Master-Barber stroke"
I missed those long strokes! Let's see how it performs