Can someone correct me if I'm wrong about the whole Steamboat Willie thing?

Hi there,

So from reading about this, my understanding is that you can effectively: distribute, copy, adapt and even sell Steamboat Willie so long as you don't infringe on trademark law.

Trademark law can include: names, logos, brands, symbols that are used to sell or market a product. So for example: "Mickey Mouse," "Walt Disney" and because Disney even uses the Steamboat Willie version of Mickey at the front of their animated movies, even the imagery of that would be trademarked, and thus, I cannot use those words above, or the imagery itself when advertising something?

Is my understanding on this correct? What about the use of the words "Steamboat Willie" itself? Is that trademarked? How far does this go and extend?