Weathering a Live Steam Engine

So here I have my nice new Accucraft Mogul that has its perfect Museum Quality Finish and although it looks nice on a shelf, it looks pretty out of place running on the track. I would like to do some weathering like I have seen done by Jack Thompson (aka Big65Dude)my only fear is that with the high heat of the engine, any paint may just flake off. Now before you post any responses, please note that my resources are very limited as I have a very demanding household (a wife and 4 kids) so if your idea would envolve spending lots of money on fancy equipment then the process most likely wont work for me. I apologize if this question has already been asked, but I have searched the forums and archive and havent seen anything about the particular weathering techniques for live steam engines. Thanks in advance for your help. You guys always have great ideas!

JT