I know those JD's well. I drove both unstyled and styled models, and the Ds and Rs. The GP's were As, Bs, and Gs also. They had the Letter on the Gasoline tank on the cockpit. The whole B, A, G, D, or R. This theme was repeated over & over. They became the 50s, 60s, and 70s, and 80s. Then the 520, 620, 720, 820, then the 530, 630, 730, 830. Then again in the 2010, 3010, 4010, and 5010 series. And so it goes.

But still, the unstyled Farmalls and Unstyled John Deeres weren't much alike, neither were the unstyled Olivers, Minneapolis Moline, Case. Fords were always different. Influenced by Harry Fergeson and their English Spin-Off, Fordson. (another Edsel by product)