It looks like interest in this thread has fizzled out, which is too bad because it was fun.
My wife and I came up with over 50 Beatles song titles to fit this cartoon including one for the entire cartoon.
If anyone is interested in our take or just want to compare notes, PM me and I'll share our complete list.
That being said, there are still two that have us stumped:
1) Boy with Girl stepping in his balloon:

2) Duck with a bag of chips (or something) on its head:

We've come up with some ideas, but they don't really seem to fit as well as the other ones.
Anyone have any clue about these two?