I suspect it is not so simple- read as impossible. Even though you could ignore the Power Reserve function, make a custom movement ring and simply be working with a date only watch your problems will still be spacing between center pinion and the date window, custom making a date wheel for the date at 6 and finally finding a correct thickness movement that allows correct alignment of the crown height with the case tube while leaving the dial at the correct height. Just go buy another rep and get the movement serviced.