I've had good results using the sort of leather cleaners sold in Auto shops for cleaning leather car seats. One brand that I use is called Decasol but I don't know if it is available in the States. I just paint it on with a brush, leave for ten minutes then wipe off, allow to dry and then use a saddle cream polish called Stubenhamenol which is made in Germany. Leaves a great finish without destroying the patina. Lagopus.....