I gladly bought a TriMotor ride at AirVenture 2018 - I got on board of my own free will 'assuming' (and yes I know what that means) that NO crew in their right mind would operate an airplane they knew was not properly maintained in critical areas....you know, like engines and such. I have faith - and at day's end that's all any of us laypeople can have - that the EAA maintains their aircraft as well as anyone in the world.
Beyond that, I'm not exactly sure what other "due diligence" a paying passenger on any airplane ride can do? Even on a commercial airliner.