Hanging blimps, dirigibles would add to the feel of the room
and would be quick gratification. You could just cut the
shapes out of pine or whatever your favorite wood is and
paint them. Make sure to use a kid safe paint.
Or how would you feel about laminating and carving a
propellor to put over the door? I wouldn't go full-size on
it. Could be fun. Staining it with Minwax stain/
polyurethane finish is really easy. I wonder if you ask
around on this list if you could find some replicas of the
decals that go on the propellor.
When I was a kid, I had a Snoopy music box. He sat on his
dog house wearing his goggles as the WWI ace. The dog house
had roundels on it and it turned as it played "Over There".
My Mom still has it kicking around somewhere. I saw it last
time I visited.
Have fun! (last year I built a rocking swan out of white
oak for my niece)
--Stephen