Hi, Mitch.  Welcome to the forum.

The two-size uppercase typeface was actually not that uncommon and was offered by a number of different manufacturers under a few different names. I believe one of its prime uses was for filling out forms, but as your sample proves, it was used for other purposes as well. The type sample you provided is slightly different from the double uppercase typefaces that I'm more familiar with - those used by Smith-Corona, Olympia, IBM - but with a little online research it shouldn't be too difficult to figure out the manufacturer that used the variant in your example. Knowing the exact model might prove to be more difficult, or even impossible, if it is a typeface that was available for more than one model.

I'm fairly certain a few such machines have appeared in the forum, and using the search tool should root them out (I'm traveling at the moment and would otherwise do that for you). Below is a 1960 Smith-Corona Portable Electric that I have with the Gothic typeface. I have a couple of other makes/models with a similar typeface but can't access images of those at the moment.