Fagen flight museum is worth consideration. It is right on the granite falls, mn airport. Almost all of their aircraft are actively flying, 11 WWII aircraft. Two p-51, two p-40's, p-38, wildcat, b-25, pt-19, pt-22, pt-26, bt-13.
A lot of war artifacts professionally displayed in 4 huge and beautiful hangars.
Runway is in fair condition- kind of bumpy. $3.75 100LL as of last weekend.
Http://www.fagenfighterswwiimuseum.org