Thanks for all the responses. Looks like it's all for the bottom smaller tire. They are different sizes so I'm not gonna use one of each, at least not considering it now. I do agree that the sidewalls and front/rear tires are different. The bottoms have a 17mm ID while the tops are 15mm, so the same rims aren't going to fit both without some work. The OD is listed as the same for both on this page, but the 50's tires are slightly larger.
I ordered the top tires, the "a 1 Ton truck tire", as the one that seemed to match my "scaled" sizes off the photos. The bottom ones, called "a 50's style 1 Ton truck tire" as a second chance being close in size. From Ma's Resin.