In my opinion that is a very special revolver, congrats............
The Second Model 6.5 inch target is on the right, next is the Second Model 5 inch target, next the Second Model HE, and then the 5 inch Heavy Duty. Based on the position of the lettering I would say an original 5 inch barrel and not cut. But I'm open to other interpretations if anyone wants to share.
. . . They may have been forged with a 6" forging die because Smith didn't have an N frame 5" barrel forging die. So it had to be cut. Therefore 5" barrels were factory made and properly factory roll marked . . .