Back before 1973, Ruger did offer the .44 Magnum in a gun they called the Blackhawk. In fact, they got the gun on the market slightly before S&W got their Model 29 on dealers shelves.
In 1973, Ruger changed the lockwork design of their SA guns. All the Blackhawks since then were named "New Model Blachawk", and the older guns came to be referred to by collectors as "old model".
The Super Blackhawk in old model configuration is very rare. The New Model Super Blackhawk is what is commonly seen. For many, many years it was only available in a 7.5" barrel. Today, several other configurations are available. Today, you can get a Super with a fluted cylinder and a round trigger guard. Stainless, if you want. Factory made to mount a scope, if you want. And, I understand there is also a "Blackhawk" model available in .44 Mag now, too.
The Super Blackhawk uses the New Model Blackhawk frame, but had a different (steel, dragoon style) grip frame, slightly longer than the regular Blackhawk. Grips do not interchange. The Super also had a non fluted cylinder, and a steel ejector rod housing (for added weight), and a lowered hammer spur and a grooved trigger.
There are several different guns found as "Blackhawks", the original, "flat top" old model, the New Model, and today some anniverserary guns made with old style frames and new style lockwork. I'm sure there are some variants I didn't mention, I'm not a Ruger collector, just an aquirer.
IF there is one thing Ruger sucks at, it is naming their guns so you can tell what they are in casual conversation. The Blackhawk is bad enough, but the Vaquero is worse!
With all the different variations Ruger has added through out its production history, the only way to be sure which "model" is to read what it says on the frame. For many many years SBH was easy to tell at a glance. Not so, today. If it is a .44 Mag, has a non fluted cylinder, and a dragoon style (square back) trigger guard it is a Super Blackhawk. If it doesn't, it still might be a Super, or it might be just a Blackhawk....
clear as mud, right?
To further add to the mix, used guns are sometimes found with replacement grip frames and other features. A friend of mine (a while back) picked up a pair of "Blackhawks", with 4.5" barrels, free spin cylinders, and BIRDSHEAD grip frames. Chambered in .44 MAGNUM!
Correction: Now that I think on it, I believe they were not blackhawks, but Vaqueros...
And, he had a Bisley hammer added to one of them, for easier cocking with his short thumbs!
He hit me up for some ammo, and I gave him a box of LSWC reloads (240gr @1100fps). He told me afterwards how nasty the recoil was, and I advised him never to shoot the full magnum stuff. As far as I know, he hasn't shot them since. They look pretty, but are possibly the worst set up for full magnum power. My guess is the guy who had them set up that way played low power cowboy games, but got them chambered in the magnum, just in case he ever needed it.
Anyway, a used gun can have almost any combination of things from base stock to full custom. And may have been through several owners before finding its way to the shop for us to see. They can go from looking beat up, and still be perfect mechanically, to looking like new and having been heavily used/customized, and everything inbetween.