Thanks for the leads. The Vauxhall comment led me to Opel then GM and then the Camaro. It is bumper for a 1967 Camaro. The wrapping of the bumper changed in 69. This one will fit the 67 or 68 Camaro.
The Vauxhall bumper has a distinct pointed centre whereas this bumper comes to a point but is a straight line from each end.
That's from the 1958 Borgward Isabella Princess Edition.
You might try selling it on eBay or similar with a lot of pictures. Somebody who wants it will pipe right up...