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Wow, a nice gun. First, the brass grip frame was added after it left the factory. It may be a factory made grip frame, but it wasn't shipped with it. If it's a Super Blackhawk, (not an older Flattop 44 Blackhawk,) it was made in 1962. It would have to had a little bit of cylinder turning to allow the dis-assembly & re-assembly when the grip frame was swapped.
Condition is very important. And, if it has the original box & papers all adds or subtracts to the value. In the case of your serial number, the original box would have been known as a "white box" variety if I recall correctly. Those boxes carry serious value.
Now, to help us determine a value, we'd need more details. Plus, if possible, serious close up pictures. If you need to see how to post pictures, go to the Gallery section here, look at the "sticky" at the top & it'll tell you how to post pics.