Join Date: Mar 2012
Location: In the wee woods north of Napanee Ontario
I always am leery of adding anything to leather that softens it.
Old leather that is brittle tends to become soft and bits flake off with handling. Adding oils darkens the leather considerably but leather has no memory and does not retain shape well.
I would suggest only Renaissance wax that is a surface treatment that does not soak deeply into the leather. It protects the surface from humidity and handling and does not darken leather nearly as much as oils do.
I one did use oil on a very dry sword grip and the leather was rolling off in bits whenever you held it. The leather fibres over time deteriorate and no longer have their strength and can turn to dust.
You can only revive modern leather to a degree, very old leather I've soaked in oils only to have them crack/break on WW1 saddle straps.
It really depends if the leather was stored well or not that dictates its current condition.