When I was taking a few notes about Ashigaru, Japanese foot soldiers of the jigoku-era, I found that most contemporary illustrations on this page stem from one and the same book by Utagawa Kuniyoshi.
The main source for the Wikipedia article, Stephen Turnbull, references in his Osprey works to a book called Zhôyô Monogatari. This is also the source for quite some of his contemporary illustrations, that seems to have a very similar style to the works of Kuniyoshi.
Turnbull cites in the further reading section in the "Osprey Warrior #29 - Ashigaru", that his research is based on Yoshihiko Sasama's research. The latter uses this Zhôyô Monogatari as one of the main sources. A search on Pinterest reveals quite a lot of pictures are contained in this elusive essay.
Using Google Translate to get monogatari in Kanji(物語) and the Japanese Wikipedia on Ashigaru, I was able to discern the original (or modern writing) title to be "雑兵物語", but that is a redlink. Google helps though, that it is to be read as Zōhyō monogatari. Note that the Zōh/Zhô seem to make no difference for the pronunciation (though it might be a typo).
Only the search for Zōhyō Monogatari did show further results though: there seem to be 3 (modern-ish) editions (1776, 1967, 1977) listed in the WorldCat.org, but all of them were listed only as "Japanese".
Now, I was wondering if this manual, the 雑兵物語, was ever translated as itself since my Japanese is pretty much not suitable to read it.