Here's a rear bumper core recently removed from a 1964 Grand Prix. Does have pitting on the inside but no rot, does need straightening and rehrome, one bolt stuck in the hole.
Look at the enlarged pics to see exactly what you're getting. You get the part pictured. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Exterior Parts & Accessories\Bumpers & Components\Bumpers & Reinforcements". The seller is "wscomics1" and is located in this country: US.
This item can be shipped to United States.