The first venue for the mixed-up meetup is Wright-Patterson Air Force Museum. There is no entry fee for the museum.

https://www.google.com/maps/place/National+Museum+of+the+US+Air+Force/@39.7807961,-84.1115705,17z/data=!3m1!4b1!4m5!3m4!1s0x8840832fc83ffd85:0x71e29a127c5a32c9!8m2!3d39.7807961!4d-84.1093818