I recently bought a 1981 Trillium 5500 with a well maintained Brown 4 burner stove with oven. Everything works! Instead of just using the oven for storing pans I though I might actually bake something! The rack is missing!
If all else fails, a welder may be able to fabricate one for you. Thay can make just about anything! Where in Washington are you? Anywhere near Seattle? I would LOVE, LOVE, LOVE to come and see your 5500. That is my next trailer.....