It has been my experience with a saddle this dry that Proofhide just does not do the job. I brought a saddle in similar condition back using Gloveoleum. I applied a coat to saddle, then used the shop towel I had used to apply the Gloveoleum to wrap the saddle and placed it in a plastic bag for a couple of days. Repeated the process several times. Of course the cracks did not go away, but the saddle recovered nicely and it is very rideable. Once done, I did apply Proofhide.