There are currently 5 ways to customize weapons in the Weapon Customization system: Paint, Spray, Material, Camo, and Wrap. I would like to propose 2 more: Decal and Engraving (which might, in fact, be combined into one).
“Decal” would place a colored sticker/decal on the butt of rifles and shotguns (probably not on all due to the nature of the stock, and not enough room on handguns and bows). These would be, for example, icons of favorite animals, reserve logos, Diamond or Great One medals, potentially awards from community events (e.g., “Halloween 2023”), etc. Ideally players could rotate and perhaps position them where desired, but this might not be technically feasible.
“Engraving” would essentially be the same sort of thing, but would be engraving on the wood finish, rather than a colored decal.
I have made a mock up of an example using assets from Classic to give an idea of what I mean.