David,
Do you know what kind of leather it is (ie mineral tanned, vegetable tanned, etc)? A good clue at this stage: is there any fine, reddish powder or areas where the leather fibres are very loose? If you can look at a cross section of the leather at all, is the inside a light blue-green colour? Is the leather 'finished', or is it like suede?
Any leather treatment depends on the kind of leather, and how bad a condition the leather is in. If you let me know the answers to the above questions, I'd be happy to check my notes and let you know (I recently completed a course in leather conservation).
Sincerely,
Uniclectica Antiques and Collectibles Online
http://www.interlog.com/~uniques now searchable!
