I guess I have two questions.
First, how authentic is Lonnie's to a real Chicago hot dog? I'm from the New York area and Chicago style foods remain something of a mystery to me. Brown mustard and kraut on an old beef hot dog with natural casings is what I'm used to, but these were actually quite different. Good, but different. I don't know what the history of these are.
I was also curious about the celery salt. That struck me as an odd addition. Any suggestions on what to order there. I don't recall the names of the streets I ordered, but the one was the dog with the kitchen sink on it, and the other was with mustard and kraut.

I will be back, but my experience there did give rise to curiosity.