+1 on the Zaino! I used it on my mom's car a few weeks back ('96 Mercedes) and it seriously made the leather look almost new again! Zaino IMHO is the best for almost all cleaning jobs for the car. Try the Z9 & Z10 for your leather! O yea, and it smells great too....
INFUSION WORKS HAS NATURAL LEATHER CLEANER AND CONDITIONER THAT NOT ONLY CLEANS THE LEATHER, IT ALSO HYDRATES THE LEATHER TO PREVENT DRYNESS AND CRACKING. CHECK OUT THE WEBSITE: www.infusionworks.com