Just decided to draw the three different versions of Dinsey's Casey Junior.

Top left: Casey Jr. from "Dumbo."
Right: Casey Jr. from "The Reluctant Dragon."
Bottom left: Casey Jr. from the Casey Junior Circus Train ride in Disneyland California (there's another one in Disneyland Paris, France).

You can see that there were many differences between all three. In the film, "The Reluctant Dragon," Casey Jr. has a front window on his cab, is lower to the ground, is shorter, is equipped with a bell, and has different shaped eyes then the other two. In the film, "Dumbo," Casey Jr. no longer has a bell or a front window on his cab, plus he becomes somewhat taller and longer. The Casey Jr. used for the Casey Junior Circus Train rides has the most changes. The ride version of Casey Jr. has a more realistic dome and whistle, he also doesn't have the platforms on his boiler, and is also lacking a mouth and his wheels by his cowcatcher. He also has different shaped pistons and his coupling rods are arranged differently, not to mention he's missing the platform on top of his cowcatcher. He also has his name written on him and the initials of the Casey Jr. Railroad painted on his tender, not to mention he has the number seven on his hat witch has a much different shape. His eyes are also shaped like cones and he has a more realistic shaped smoke stack that has a circus like design on it. There are more differences between the three when you see them in color.