I am so loving this. When I started planning my BigBang, I briefly considered this era, and the idea of "Steampunk Sam" was (is!) just too perfect. I ultimately went a different way (and about 40 years earlier) into my own AU, but I like how you've integrated the AU, the show, and the era. Of COURSE Dean has a wicked cool automobile. :D Voices (esp. Dean) are on target.