Things that are wood or have a soft top should get car house priority. Maybe other things can be rotated in and out. Freight cars and diesels look more authentic with a little wear anyway.
They may look authentic with faded and peeling paint, weathering, and rust. But try explaining that to your volunteer crew who have worked 2-3 years on the restoration. "By the way, guys, we have time for one more job before we start over on this one."
Bob Kutella