Yes, I believe all of the airplanes were in flyable condition and it would take little time to gas them up and go.
About 20 years ago, before it went public, we took a private tour. There was a B-17 ball turret on display. As we noticed how little room there was in the turret, it turned out this short old guy in our tour group used to be a B-17 turret gunner.
Edit: From Museum of Flight: The average B-17 crew size was 5’7” 127 lbs., and the smallest guy in the crew was the ball turret gunner.
I'm going to miss this place. I'm a fan of WW2 stuff and regularly play World of Tanks, World of Warplanes, World of Warships games.