I am not sure. It almost reminds me of an Andalusian, only darker. The comb looks really weird. Can you tell what kind of comb it is? It kind of seems to have a game build. I hope someone can tell you.
Yes, where did you get them. To me they look like Blue Hamburg, but they don't have the white earlobs. I would guess a cross/pure standard or game fowl. They do appear to have a blue gene.
Because of the rose comb and build, I think they are hamburgs. Black Hamburgs....any blue color that I have seen in my chickens is very gray-yours are definitely more black in the pics. Here's a great article on combs: http://www.backyardpoultrymag.com/issues/3/3-1/Dave_Anderson.html