I'm not sure if you can. Are the rips clean through the leather? What exactly is leather restorer and what normally is that used for? Is it some kind of oil or wax?

How often do you plan on riding the saddle? I have an old B15 in good but not excellent condition but ride only occasionally (I "restored" it with Proofide). I honestly don't know what you can do about the cracks except live with it and save your pennies for a new one.