When cleaning up the original feet textures I went a bit overboard and made them much too flat.
As someone who is not into feet at all (talking about myself here) I didn't give it too much thought.
Thanks for the valuable feedback by user "Canadadry" who IS a foot lover, giving me insight in how a foot texture should look.
It still doesn't include normal maps but I might add those in a future update. Since creating normals for this look is quite some work and not strictly necessary for this kind of style, it would be a nice extra and give it more depth and detail.