Hello, I want to condition the rubber on my 1981 MB 240D. It is 28 years old, obviously, in very good condition overall, but in a few spots looks like it is starting to develop small cracks. Ive done all the reading about silicone, petroleum distillates, etc., but it seems that most of the discussion and conversation focuses on modern silicone rubber. Would a 28 year old car use silicone rubber or would there be a potential for natural rubber to be used? Would the age or potential composition change the products to be used? Krytox and 303 are my choices. Thanks!