The Air Force museum is free
and has been expanding.
It is really great !
Speaking of museums and now defunct automobile
manufacturers, the pictures on that website of the Duesy museum remind me a lot
of the Packard museum, which I believe is in Dayton, Ohio. It's been a
while since I was there, but it was pretty neat. They even had some
airplane engines and such that packard helped design during WWII (I believe they
had an Allison engine like that used originally in P-51s and I think they had a
turbine or two as well, among others). If you're ever in Dayton, it's
worth a stop...and while you're in Dayton, you might as well stop by the Air
Force museum as well...last I knew it was free to get in and worth every
penny.