One more thing... All the New Model Blackhawks, Super Blackhawks, and original Vaqueros share the same cylinder frame and cylinder. Called the large frame. Grip frames and hammers are interchangeable on the frame. The .44Mag 50th Anniversary flattop is also on this frame (think there is a .41 Mag out there floating around too). Any .44Mag that is floating around out there is on the large frame. No exceptions.
The there is the medium frame which is used for the New Vaquero and a few of the new 'flattops'. For example I just got a new 5 1/2" .357/9mm flattop from Lipseys. And the catalogued .44 Special BH flattop. Lipseys also made a run or two of .45 Colt/45 ACP flattops. The OM (three screw) .357s were all medium frames too.
Then there are the small frame, for the .22 Single Six, .17, .327 Single Seven, and .32 H&R mag Single Six.
Note that most all (if not all) the GRIP frames can be interchanged on all of the above frames. That is NM grip frames to NM frames.
Finally, the Bearcat .22 which has the smallest frame all to itself.