There is always one thing that makes every weapon unique. It's owner. The fact that THIS weapon is YOURS is all the uniqueness you need IMO.

It fits the New Vegas motif better, but a six shooter named The Duke. Mirelurk shell inlays on the grip. Deathclaw leather holster. Well oiled and as untarnished as if it were manufactured yesterday.

That's to keep locals uncurious about the contents of my pockets. Or for the odd wasteland trade gone sour.