Genuine Mercedes high mileage award grille badge made by J. Preissler.
They made enamel badges for Mercedes and other makes including BMW since at least the 50’s.

This one is the original version before they went to the bolts through the badge.
It is in great enamel condition no chips, especially the the white star.
The only thing it needs is to fix and add a thread.

It is about 3 inches in diameter