If the leather has dried then there is only one product to try brfore replacing. I have used this on two cars that the leather had cracked.
http://www.performancemotorcare.com/aca ... QgodGFJfJg
It also brings back the smell of the leather and lasts ages. Hope this helps. You will need to buy both products for it to be effective though.
I have not purchased anything from the above supplier but i think www.cleanandshiney.co.uk now stock this product and are normally next day del.