I forgot to dimple the second hole from the left (it holds the platenut)-

I started riveting the 470 4-5's on the bracket, and realized it after it was too late. So after studying the plans, and looking ahead, I decided to put a 470 3-4 (cut down a little to about 3.5) in the hole with the manufactured head on the inside, and modified one of my flat sets to squeeze the shop head. Here's how it looks now-

Here's how it should look, done properly on the other side-

From what I can tell, this will not be in the way of anything, and it's just holding the platenut in place.
Like I said, I think I'm ok here, but I wanted to run it past you all...