Captain April Vs Captain Kirk. Nice... This or Khan would be quite cool. It does seem a bit too obvious to leave a piece of concept art lying there with a Villain's name on it. I mean, why not just put Harrison's Gun on that piece of concept art if the Character is going to remain as Harrison till a later reveal.
Maybe April owned or invented that gun but it was taken by Cumberbatche's character from a museum or lab.
Good show JJ Abrams. This kind of speculation is frustrating yet a lot of fun.