2:1 ratio right? (Two brains from the animal will tan one hide)
Damn if I know. I grew up around leather, but we sure as hell didn't make it from scratch. Kinda why I don't take about 75% of the suggestions too seriously... was always around it and it really doesn't take much to keep it supple.
It's one of those funny topics that seems to foster polite debate...if it wasn't milsurp, we would have not been as polite I suspect.
We had Dubbin, Saddle soap, mink oil, neatsfoot too IIRC. Never really saw much difference. Except that ( As I mentioned before) I like the thicker viscous solutions, prolly just because they are easiest to handle and use.
Someone will be along to pimp their fav...but there is no way I would vary from the museum standard. If they have no standard...go with an average of what 3 or 4 reputable museums use.
The advice here is just too person specific, it's like hanging venison. Everyone is gonna be right and argue their position...because they cannot be proved wrong. But on the flip side...usually cannot prove that they are correct either.