Looks like ODV-003 and RDV-004 to me which is normal for that year.
As I understand the theory.... "The half dollars for 1971 were the first to be coined in copper-nickel clad composition. The harder alloy required some modification to the half dollar, a slight reduction in the overall size of Kennedy's portrait, they also displayed much broader boarders."
I do think there are 1971s with ODV-002 though both Philadelphia and Denver as well as San Francisco, Variety Vista seems to acknowledge it at least. Not sure when they changed the design from ODV-002 to ODV-003 though. early mid or at the end.