I had to fold some empty columns into each other to make this picture fit, but it shows that Dad soloed after 8:15 of instruction, then went to Pontiac MI and rented a plane after a fifteen minute checkout. Shortly after, he went to Gulf Field in New York and was rented a plane after a five- minute checkout!
This would be unheard-of today, but was quite normal for the time.
As an aside, Gulf Field was several miles due west of Zahn's Airport, which was quite a hub of activity in the mid- 1900s. As I understand it, Gulf Field sold Gulf gasoline for quite a bit less than what was available at Zahn's... It wasn't much more than a fly- in gas station.