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

Yup, they´re copper plated beneath that "beautiful" salmon colour 

Have stripped quite a few myself, which is easily done with paint stripping gel, as long as it hasn´t been fired yet.
Somewhat harder, if the paint has been burned on there on a used engine.

Here´s an example of the chimney, before and after stripping with Morse Paint Stripper:
(Attachment Link)