72 GMC Rear emblem facts

[72GreenMonster]

Looking to re-attach or re-glue.
My Sierra emblem has the original posts and came off
with some adhesive.
Pretty sure this was original as I know the PO
and truck very well.

Went to Brothers Trucks and they swore up and down no adhesive was ever used on the model emblem "Sierra" in my case.

Any historians out there and I still need an adhesive to secure these emblems are heavy as they come so even if they didn't what hardware is used or adhesive in the restoration world?

Thanks and sorry for the rant