Hooded rings speckled with pits turn up from time to time. Same for the parking light bezels although I've seen a couple really nice parking sets turn up on ebay in the past year.
All of these recently have/had parts cars, year(s) unknown:
Smitty’s Salvage 800-236-6892 Wisconsin
Windy Hill 320-354-2201 Minnesota
Whiteside 360-668-5248 Washington
French Lake in Minnesota has a '55 but from a photo posted here several months back, those bezels were gone.
Another long shot is Duane Hayes parts cars
donegoing2002@yahoo.comI'd be very cautious blasting pot metal. My understanding is behind the outer "skin" of the casting, the metal becomes more porous & softer.
Since you're looking to paint, you might want to check out some specialty chrome substitute paints from Alsacorp and possibly skip the blasting. I tried their "Clear4chrome" to seal a variety of NOS cast pieces already showing tiny pits from just sitting in the boxes for 60yrs. Can't speak to longevity yet but it went on very thin & looks nice.