I can't help much as I'm very new to all this but I've been playing around with neatsfoot oil the past few weeks and have found results can be inconsistent. I had two separate pieces cut from the same hide and not dyed. Oiled both in the same way (same bottle, same applicator same number of coats). One looks like a slightly darker shade of natural leather as I expected. The other looks like it's been dyed light or medium brown. Very similar to what you're showing but perhaps a little more contrast between them)so I'd be interested to hear the how's, why's and any fixes (though in my case they weren't going to be used together so doesn't matter).
