I used these aluminum brackets in the 1" size for mounting two badges on my rear bumper:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
I used three of the brackets because the Capital Area Cobra Club badge had only one stud centered, and the Club Cobra badge needed two since it has two studs.
The car has covered about 6 or 700 miles since they were added; no casualties
Here are some pictures of the result: