Should be Super Blackhawk and Old Model Vaquero. The Old Model has a larger frame, I believe, as compared to the New Model
I have the Uberti Buckhorn 44 Mag revolver with a 44-40 conversion cylinder.
As usual, only 44 Mag/44 Special for the same cylinder. The 44-40 is a separate cylinder.
If you order a cylinder for it, either-or, you will have "fit-it", or get it "fitted", more than likely.
44 Mag revolver with 44-40 cylinder, loaded with custom HP loads.