Engine Compartment

Here's what I did on my om 66 Sat. De-grease, scuff. Then I went to Napa and got the chick to color match my paint. 3 or 4 cans ( they make rattlers in house) mask it off, got my firewall foam kit, and boom, looked 500% better

I had a local auto / paint store mix up the EV2 I need put in cans.. What's a firewall foam kit..?
I might be a bit dumb, but I'm almost thinking I'd leave the firewall alone.. It still has the factory assembly line "X's".. Kinda hate to see those go... guess it doesn't really matter...lol
What grit sandpaper you use..?