I have Dunhill for Men and I tried Edition (from a decant someone gave me). The scents are not related in my opinion, I love For Men, didn't like Edition all that much (although it's certainly a quality scent). Sorry, I don't have the vocabulary to describe the differences accurately. For Men is rather subdued, Edition is more spicy.
Dunhill For Men seems to be in production: I can buy it locally (here in The Netherlands) from the shop behind www.parfumerie.nl. That shop specializes, among other things, in difficult to find classic fragrances. It's the only brick-and-mortar store I know where Dunhill For Men is sold.
Dunhill Edition I've only seen on eBay, I know for a fact that the person who gave me the decant bought their bottle on eBay.