Advance Machine Company, Chicago, IL, c. 1916, 25". This is one of several wall-mounted single-column "unit" machines made by Advance from the (I think) late 1910's/early 1920's through the 1940's or 1950's. The different models differ by height, depth, mechanism, type (or lack) of window, and the location of product exit slots---but other than that they're identical! I can't keep the model letters straight, but they're described in Silent Salesman Too (page 13) if you want to investigate.
This is the earliest of the unit models listed in Silent Salesman Too. Although all of these models differ in some way, this is the most different. At 25 inches it's about 8 inches shorter than the others, its depth is less, it has a flat bottom, it has an Advance #4 mechanism, and the product is dispensed above the mechanism rather than below it. In my opinion the machine's smaller size makes it cuter than the larger models, and the #4 mechanism gives it an earlier look. That is, it's an earlier look if you know the #4 mechanism came before the later flush-mounted mechanism found on the Advance Model D. If you don't know that then it won't look even a day earlier.
For comparison, you can see one of the taller, deeper unit models with a later mechanism here.
All of the Advance unit vendors---including this one---are made of sheet metal. They were originally stenciled with a slew of patent numbers on the bottom of the machine, so if those are missing then the machine has probably been repainted at some point.
The machine pictured above is 100% original and is pristine in every respect. It has the expected patent numbers stenciled on the bottom, nearly intact paper on the front of the back plate (click here to see a dense image that you can expand to read), and a little notice at the top of the inside stack. Condition-wise, it don't get no better than this!
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