Does your fixed sight "Pre War" above not have the V-notch rear sight and narrow little tapered front blade? I find these very difficult to use, even compared to percussion guns.
I have to amend my earlier statement. The only Uberti's I've seen that didn't have the pinched frame sights are the Evil Roy models from Cimarron.
Cimarron's "Pre War" is the "New Model" that is, the pre-WW II Colt design, with the square notch and Patridge front sights.
As I've said, I have never, to my knowledge, seen a pinched frame revolver, only photos dealing with that Colt model frame. All the single actions I have ever owned either had the late Colt SAA style sights, or had Flat Top frames or adjustable sights.
I had a Colt New Service with the U-shaped rear and Vee type front sight. Had a hard time holding elevation and soon replaced that. This was not a pinched frame, however.