BIOPIC CAST HELP!

I had met with Walt Disney's daughter, Diane Disney Miller, and I told her my idea for a WALT DISNEY BIOPIC....
I told her that I have a script, and a cast, she said great send them to me,
I have a script, but the cast list still has some blanks, please help fill them in!

Here's who I need: (Keep in mind all must have some resemblance to original people)

Walt Disney: (actor from late 20's-early 40's with a warm uncle or grandfather like personality):

Young Roy Disney [brother](Same age as Young Walt, try to get the actor to look like Jeffrey DeMunn, since I cast him as Older Roy):

Lillian Disney [wife](I cast Connie Britton, but maybe someone else could do better):

Dick van Dyke (not as well known actor, an actor in made-for-tv movies and small parts in movies):

Julie Andrews (not as well known BRITISH actress, who is in made-for-tv etc.)

Flora Disney [mother] (older/mid aged actress):

Ron Miller [son in law] (well built/handsome young actor not as well known):

Robert Brown [son in law] (handsome well built young actor not as well known):

Adriana Caselotti (late teens-early 20's/Italian looking):

David Tomlinson (mid 40's-late 50's/ British):