Hello, I just purchased an older Bachmann Big Hauler engine from a friends grandfather who passed away a year ago. This is a electric #12 Denver & Rio Grand engine and tinder. I do not have it in my hands yet but, it is on it's way to me. It's a G scale I want to put on a shelf mount in my home. I believe the engine has smoke but, from what I see on you tube, I want to upgrade the engine smoke system. How is this possible and what is a DCC?