Its not difficult to find new condition guns from that era. First, however, lets destroy the idea that guns are unfired. With few exceptions, new guns are all test fired at the factory. Anytime anyone says a gun is unfired, you should question their knowledge and honesty.
While I like my antique or nearly antique guns to come with their box, when you get to the 40 year old guns and newer, its not really worth so much due to the large numbers of both boxes and guns still floating about. Asking prices usually are about $50 higher with the extra's, but often don't realize that much more. Its commonly only a situation where those guns sell easier or faster.