I have no idea about vintage card shops in Las Vegas, but if you're in to vintage
anything and in Las Vegas, you MUST go to the Bauman Rare Books in the Venetian. Absolutely unbelievable to look at the inventory they have.
http://www.yelp.com/biz/bauman-rare-books-las-vegas
They do have some items that are not books, but I think I'd remember if I saw any cards. If they did have any cards, they'd probably have a T206 Wagner.