You can try Neatsfoot oil, get the pure stuff and not the "compound". Apply it sparingly to the flesh side only, a little at a time, let it soak in and do this as many times as is neccessary..........if you go too quickly at it, it overwhelms the old leather, leave about 24 hrs between sploshes is best, and have it somewhere that's not hot and dry.............move it about as little as possible 'till it gets supple, likewise with strenuous rubbing - wait 'till it gets supple of it's own accord; slow and gentle are your friends here...............hope this helps, atb mac