I'm looking for any recording of the Day at the Races show in Chicago, early 1977. This is the show where someone dropped eggs on the stage from the balcony and they stopped the show temporarily after Brian slipped on the broken eggs and fell.
You and me both, my friend.
No tape of this show has ever come up, but it's worth noting that a tape of Thin Lizzy's opening set exists. Track down that taper and you're good as gold.