Yea, i got two grilles when went to the Mopar Nats. One was all broke and in bad shape so i used it as the donor grille. Then i found one in good shape as the main grille.
The adhesive stuff i used was a stuff call Plast-aid. I would say any two part epoxy for plastic that you can get at any auto parts would work. The only thing the Plast-aid had over that stuff was you can make parts too. Here is link to a site of this stuff.... http://www.plast-aid.com/index.html