Well, I dunno. I think they suit him, since he's been stuck in a coffin for god knows how many years. I bet he still has one of these babies too: http://tinyurl.com/2czqzb6
Hehehe. Goodness me-- I remember having an old Nokia.
Vincent may have been in a coffin for nigh on half a decade, but in the FF7 universe it's quite clear his weapons, evident from his flashback in dirge, are fairly modern. Vincent was also a member of the Turks, giving him access to next generation technology as part of that task force. So if you think about it... last generation's next generation is this generation's modern standard. (In theory. Often the weapons he would probably be given would be prototypes of the models available today.)
However I digress, for it's pointless to make the above point when he is acquiring modern weapons from shops across the land. Go with the modern weapons is my vote.