Grill work

The problem you're going to run into, especially if you take EVERYTHING apart, is that the heads on replacement bolts you can readily find at the hardware store aren't going to fit in between the rolled double lip on the inside of the aluminum trim. Regular rivets will work for the rest of the bracketry.

I found some suitable low profile flat top studs and 6-32 nuts at Fastenal. They were indeed pricey but they worked great for HemiJim's front grille assembly. I bought a few extras for later resto projects just because the place is a 30 mile drive. I'm sorry I didn't get any close ups of the replacement hardware I used but the above links should help.