Engraving won't hide or remove the pitted steel underneath. I think it would look even worse.Then, there's the "other" option.
Send it to an engraver. The scroll work should cover most of the pitting and hide the imperfections.
A rather expensive proposition, but at least one that might actually improve the value of the gun.
If it were mine, I'd get it bead blasted and then hard chromed.