An unsigned doodle of a craggy, mustachioed face that turned up at auction a few weeks ago has been identified as the product of a famous circle of friends.

The Calder Foundation in Manhattan paid about $4,800 for the drawing at Thomaston Place Auction Galleries in Thomaston, Me.; the catalog had described it as a portrait of the French artist Fernand Léger by his friend Alexander Calder. But the foundation was wary at first, since the market has become treacherous.