If you want to make the leather nice try the leatherique line of products. They have stuff called rejuvinator that can make leather that feels like cardboard new and supple. They also have crack filler and dyes to make it look as good as it can feel. Their website has a LOT of good info on leather care and they are very helpful over the phone, leatherique.com
No, I am not a paid endorser, just a user that was very impressed with the products. As for the shift knob, get a pair of driving gloves, maybe that can help and it will keep the interior cleaner.
David Teitelbaum