We patched large holes with inner skin aluminum and cover areas that had lots of screw and rivets holes with Aluminum Trim 24" colored in almond. This is what contractors use when they are installing siding on homes. It's very thin but when you install it over the original inner skin it lays nicely.
Then we primed and painted all the walls. We didn't remove the vinyl. The raw aluminum you see in the end cap I installed because our original end cap was busted.