Boothby's
From Jenny Everywhere Wiki
Boothby's was an auction house in Reality Z-25 31-H. When it came up for auction there, Lady Catherine Maxwell bought Solomon's Diamond back from them in order to return it to the Koravi. (COMIC: The Danger, the Diamond, and the Dowager)
Behind the scenes
Boothby's acts as a fictionalised analogue of Sotheby's.