Nice score!
Don't toss that cooking grate.
Spray with some oven cleaner, then put it into a garbage bag in the sun.
30-60 minutes later, scrape the crud off with whatever you have on hand.
Hose it off, then see how it looks. Spray some Pam on it and that will prevent future rust.
I also like to hit it with a weed-burner.
what grate is THAT? I like that one a lot !!!!!
Ya ... I, too, am curious.