That's some good metal prep.
What are you using?
I'm gonna go out of my comfort zone here and say, I dont like the open look.
Skin it with 030-020 aluminum & one million pop rivets to attach it.
No issues with dissimilar metals touching and light as a pop corn fart.
Or better than pop rivets, use aircraft rivets. Much cleaner on the underside (and top) but kinda a PITA to install.
Man you need to move to Ca, or better yet I should just move to your neck of the woods.
I could have that done and bad *** in a day.