Superblackhawks could be had in shorter bbl and fluted cylinders, those models came without the Dragoon style trigger guard.
A new model frame will interchange though, from Blackhawk to Superblackhawk (non flattop models- am unsure of those).
Old Models, the frames were different (Blackhawk and Flattops smaller and aluminum).
My dad has put stainless Superblackhawk frames on all his stainless Blackhawks.
A standard production SBH is a nice gun, but they don't command premiums, even though the Blue Book says that "pre-warning" New Models fetch more.
If mint it might get 25-50 bucks more in my area (but many customers won't pay the diff, could care less). I sold my Pre warning New Model SBH a yr ago, during deer season, with grey lam grips and a trigger spring kit, it was solid and tight, had just a little muzzle bluing wear from prev owner. It shot fanstastic.
I got $315 for it, after it sat in a shop for a month.
Rifles being legal here now has hurt the .44 handgun market some (depending on gun- pre lawyer lock Smiths fetch silly prices).