When the flight team competition was hosted by I believe Lewis University, Rudy Frasca of the Frasca company hosted a small party at the Frasca airport there in IL.
We were able to wander around looking at his rather large personal collection. There is a Swiss (I think?) fighter there that is one of just a couple in the world. He has European tourists travel to America just to gaze on it.
He also has one of the T-6 Texans that was converted into a Japanese Zero for "Tora! Tora! Tora!" in addition to an unconverted texan, the last model number of Spitfire (has a much larger engine than the ones that saw combat), as well as a plethora of other aircraft including a few German designs (he was also in the process of building I believe a BF109 from scratch).
This of course was in addition to a large numbert of simulator and airline museum pieces. There was also a Wasp Major radial engine (4 row!), a biplane powered by a ford inline engine (complete with radiator that had a hole in the center for the crankshaft to come through for the prop) and others. Most of the aircraft are kept airworthy and are flown periodically.
He did have a good sized collection of rare GA aircraft as well. There were a few not quite as rare birds, but they were all interesting.
Wish I had some good pictures from that.
That might have been the same competition when a guy with a P-51 brought his bird by for a small private airshow, he also took one of the students along with him for a ride.