If you are in the US (you probably aren't), you could try local Salvation Army, Amvets or Goodwill stores. I'm thinking of old luggage which had these kinds of things on them. Also any other second-hand shops and pawn shops would also be good to check out. You might have to keep it in the back of your mind when out shopping to look for places.
Yeah, they put those on amps, spkr. cabs, equipment cases, foot lockers and luggage. The hard part is going to be finding a replacement for that grill. Keep your eyes peeled. Try searching eBay for brass cabinet corners.