Agree the museum is well worth checking out. We were there with my dad last summer. Here are pics of some of the cars Mike mentioned.
The Harry Miller Club runs old Indy cars at the Milwaukee Mile the weekend after the 4th of July. Two years ago my dad got to sit in a replica of this car, the real one is in the museum at The Speedway.
The guys w/ two seaters would take others out on the track as passengers. It was great fun. (
Harry A. Miller Club. ) Sorry for the tangent thought.