Just a update. I have switched to using the Reno Engine. These engines will not be replicas of the origanal Disneyland Railroad Engines. They will also be in standard gauge.
The Eureka looks just as much like it as the Old Timer does, but I hear Preston, known for making CAD Drawings of the Disneyland engines, is releasing his drawings for free, and I think someone is using them to make Trainz Models of the DL engines. Take a look: http://burnsland.com/disneyrailroads/viewtopic.php?t=2731
Sorry if I seemed to convince you to bring your project to such a screeching halt. But it is good that drawings of the DL engines are going to be released, and hey, maybe if the engines do get made, you could make custom Disneyland skins!