Who's the resident BlackHawk expert?

Whatever. Play games

We're not playing games.

You asked about "really old three screw BHs" and then tell us the gun is marked as a New Model Super Blackhawk: two different critters.

Give us all the information (blue or stainless, frame markings, barrel length, partial serial number), clarify what you're trying to discover, and you'll likely get good answers.

It's a different gun. Not any of the ones from the original post. This is a SBH with sq trigger guard.

OK, you have answers to the SBH.

Now, give us info on the "three screw" models and we'll see what we can give ya in return.