I have never tried to repair pot-metal, which I believe the emblem is made of. There may be some technique unknown to me, but if it were me I might consider drilling and tapping the badge, then epoxying in a small diameter threaded stud with a nut. The emblem may be to thin for this though. And you would of course have to enlarge the mounting hole.

If it were me, I would just locate a different one. Good luck, Steve.