Originally the back had a provision for a stud/bolt
...pic... Looks like yours are missing
I don't know if I would epoxy the emblem to the truck
You might be able to epoxy a bracket to the back for studs?
Or just epoxy 4 nuts to the back of the emblem, run studs and flange nuts on the inside.
I just reinstalled my original badge, mine was in a little bit better shape than yours , I was able to weld new studs on the old mounts
...pic... ...pic... ...pic... ...link... I used 10/24
...studs and flange nuts...
