303 is fine on leather, but the absolute best thing to keep leather soft and natural looking for years is Nivea unscented lotion, if it is good for your skin, it is good for leather. As I said, I started using 303 on boats in the mid 1980s because it has far superior UV blocking vs Armor All or almost any other protectant. If your leather is cracked a good fix is pre softened shoe paste, available in almost any color. Rub it in thoroughly let it dry, rub it out with white terry until no color shows, after a month start the Nivea.