Best way to repair mounting bracket on 71 grille?

Not sure it's "the best way" since I'll be done in 5 mins. Modern products have come a long way as far as bonding agents

i will totally agree with you on modern products are great and faster to fix it. but when you use the modern stuff you will to at least paint it. when you use acetone with the same color plastic, you do not have to paint.( if your good enough) you can make it look like factory, with no paint. and only paint the grille where paint is required.