I looked it up...it's the standard B-man 4-4-0 and passenger cars. It is identical to the Prairie Flyer set except that it is painted/lettered for Disney. If you are concerned about messing it up, acquire a replacement tender frame at a train show and modify it.

Lily Belle is the locomotive; Walt Disney named it after his wife before he told her that he planned to lay tracks though her entire garden. (The model is HO gauge but the prototype is 7.5" gauge.) Bachmann produced a set modeling this.
My conversion bogged down with the non-fit problem and also that I need an extra hand or two to mount the couplings. We've been spending too much time up at the lake.