I recently bought new LED headlights for my '67 Mustang. The site I got them from confirmed that they fit before buying them. They are the same same diameter, but they don't fit. Most importantly, the new ones lack mounting holes to secure them to the body with metal screws. The plain ole Sylvania's I want to replace have these.

So I applied for my refund and went looking for new ones. However, all the ones I want have no mounting holes either, and the sites confirm these will fit my car. So what am I missing? How are they mounted?

 

The ring with the mounting holes is removed from the old headlight and put on the new headlight.

 

There aren't mounting holes on the headlight itself, the mounts are on the trim ring that you probably left on the old headlights.