I have seen only one gun that had plugs successfully hidden. Quite that were not so successful.
One cosmetic change that might work is to have silver shields made to cover and then engrave with your initials or COA.
Not usual but would make the gun distinctly yours. Course this would not work if you have the notion of selling, someday.
Best,
John

Humble member of the League of Extraodinary Gentlemen (LEG). Joined 14 March, 2006. Member #1.