I'm generally inclined to trust Ausir, who could probably beat Chris Avellone himself, Fallout Bible in hand, at a round of FO trivia.
If you're looking for more than that, though, just go back to the Vertibird model in the museum of technology and read the plaque next to it. Their official info didn't have the things in development until the 2080s. As it seems the museum was pretty up-to-date when DC was bombed, logic must dictate that it was a pre-war plan and that the bulk of the post-prototype work was done by The Enclave after the bombs fell. (Unless, of course, they had already been secretly building their fleet in anticipation of what was to come, but anything down that avenue of thought, however likely or unlikely, would just be conjecture.)
As far as the design goes, it isn't a perfect fit for the setting, but I've never really minded the things. Their design, along with the Enclave power armor, had a kind of ominous, otherworldly insectoid thing going for it that I thought was well in keeping with a lot of pulp sci-fi... It just wasn't drawn from quite the same vein, or naturalized into the setting as skillfully, as the pulp inspirations of the first game.