flyingcheesehead
Touchdown! Greaser!
Sounds like the Luscombe pilot figured he'd better get outta Dodge before someone was able to read his registration number. Or was he just doing a nice touch and go on a pretty summer day?
Well, it appeared that he decided to land at OSH not even knowing an airshow was there. He landed on 27, sat there for a moment - Hey, what are all these airplanes and people doing here? - and when a couple of people started running over to try and get his (small) tail number, off he went. So, I think your first hunch was correct.