Never heard the verses sung, although I lived in Marburg - where the original "Wirtshaus an der Lahn" was located - when I was a little child (perhaps I had to go home too early ...).
The place itself was - contrary to the verses - a normal family restaurant located in a very pittoresque old house looking if it could collapse every minute. Unfortunately it had to be torn down at the end of the sixties and was replaced by a very ugly high-story (for Marburg circumstances) building.
Aah, fond childhood memories...
Yours
Ernest
P.S.: Marburg is still worth a visit - nice old university town with a good folk-scene.