Plugging Leftover Archtop Holes?

Hey, all-

Could anybody direct me to a website that sells 3/8" "goof plugs" ? I have leftover holes in a semi-hollowbody archtop that I want to cover. I couldn't find any on the Stew Mac site nor through a Google search but I know they exist. I'm told they're available through electronic stores in plastic and chrome steel.

Failing that, any ideas for what to do with leftover, unwanted holes? I thought of using dummy pots & knobs or jacks, but wanted a cleaner llook.

Thanks for your thoughts!