I have an old KABAR knife that was my grandfather's. The handle is still in pretty good condition. The leather hasn't dried, and is still tight. However, it has gutted many a deer, and the handle looks like it has never been cleaned. I was wondering if anyone had any advice on the best way to clean the leather, and then maintain it once it is clean. I really want this knife to last another 50 years, and perhaps pass it on to my children one day. Thanks in advance!