Here are two great Kennedy Half Dollars . The 1964 D Kennedy and the 1971 D Kennedy Half. Possible Doubling on both Obverse. Please see pics close up provided . Thanks!
I'm not really seeing any split serifs. Read this thread that I posted a while back. It shows visual differences between a doubled die, which has full, rounded doubling with split serifs and notches, compared to other forms of doubling. http://www.cointalk.com/threads/lets-talk-doubling.224087/