You can do the saucepan test boil the fuel and see if oil is left over or even pour it on some cardboard and wait 20 minutes. As a control, pour straight fuel on the same type of cardboard and look at the difference if any after about 20 minutes.
I personally would just pour it into a jar. A lack of any tinting will give the jig away.

I'd have thought any corded power drill will turn a small motor over.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!