Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I think it is Birchwood? Super-Blue. Readily available anywhere shooting supplies are sold.
Danny has mentioned a brown patina is available from them as well, but I've never seen it.
Tell your brother I apologise...Maybe next time. He may be happy, as it still requires a good deal of work before it will steam, not just soldering all the bushes back in place....not to mention the missing safety valve. That's an easy 25 bucks if I'm lucky for the correct one. And finding one without having to but the engine so far has been challenging