I had the song from this cartoon stuck in my head lately, and the only remedy was to look it up on youtube. I think this cartoon was in a compilation of Disney cartoons I had on VHS. I remembered the song so vividly, but had totally forgotten about the accompanying story.
1. The dreaming boy's house has awesome 1950's "modern" architecture. The drawing style is so wonderfully retro and interesting. It would probably fit in well here.
2. I also like that there's some sort of god figure that creates the accessories for his dream with a giant magical pencil.
3. The adventures he has once he transforms into a cowboy aren't nearly as awesome as the song is, but has a healthy dose of good old fashioned family racism, Disney style. In the 1950's every little boy went to sleep at night and dreamed of oppressing native peoples! Oh, but it's cool at they end, cuz they smoke 'em peace pipe.
4. It's pretty sweet actually, how the cowboy is depicted as this awesome heroic archetype. Refusing reward money, preventing trains from plummeting to their doom, rescuing pretty girls with no expectation of romance. Cowboys aren't really presented as heroes like this anymore. I would chalk it up to the decline of agrarian society, and the fact that robots and heroes with actual powers are way cooler now.