I pulled this Kennedy Half form a circulated roll. I'm pretty sure its a Type I 1979-s proof. But more importantly, I think it may be a re-punched mint mark (RPM). The bottom of the "S" appears to be doubled. It does not look "shelf-like" as in mechanical doubling. Please let me know your opinion. Are RPMs collectible? If so, what value would a circulated proof such as this carry?
