Drip gasoline was found at some wells in the field where crude comes directly out of the ground into the well. Some product had high enough gravity and viscosity and volume enough to be used as gasoline. Drip gasoline is untreated, unrefined, directly from the ground product. There were a few places around in oil fields in the countryside where some of this drip gasoline accumulated. Also, some drip gasoline accumulated at the oil well site where the crude passed through heat treaters on each lease.
Some gas wells produce very little crude and are more apt to produce drip gasoline.
There is still some of it out there. It is not supposed to be used or sold. Even in the old days, very little was used as it made an engine knock more. Also, our resource noted that for the most part drip gasoline was not more volatile than refined gasoline. I hope this information is what you were looking for.