What defines a "classic" 737? Seems like that would be the old clunker that had only one primitive auto-pilot. I never flew any model of the 737 but I did fly the 727. It had a lousy auto-pilot. Then, the advanced 727 came along with a slightly less lousy auto-pilot that was supposedly good for limited CAT III with a DA. It didn't auto-land. It just flared (sort of).