Sounds about as tasteful as putting salt in a cup of coffee, but to each their own I guess... check out the major hot rod suppliers. I'm kind of surprised there's demand enough for such a thing, unless it's made as a repo of the stock cluster... those are fairly popular to use in other cars.
There is a round, chrome radio grille in the middle of a 51 Pontiac dash, but I don't believe it qualifies as "billet." I would check with 51 Streamliner.........No, but I can get you an original one for cheap!! (please?)
wrong place for bil... -explain what you are trying to do and maybe someone can steer you in the right direction