He also needs a better oil than WD40, ( I wouldn't use that on nuthin but drains) If he'd find G96, in the spray can and just literally spray the metal completely, it'll fix that rust. I swear by it, I had a rifle I traded for that was pretty badly covered with rust, and I sprayed it down for two days,( maybe three coats) and let it soak in, then wiped the rust away, it looks a heck of a lot better now.
As far as the wood goes good luck, usually it's warped and swollen beyond it's bedding, and it'll be hard to get those dudes back to original fit.