The French government has stepped in to stop the sale of a newly identified drawing by Hans Baldung, according to the *Art Newspaper, *throwing a last-minute wrench into what was shaping up to be a major Old Master auction in Paris. The small portrait, dated to 1517 and attributed to the German Renaissance artist, was slated to hit the block at French auction house Beaussant Lefèvre, carrying an estimate of $1.74 million to $3.5 million. Two days before the auction, France’s culture ministry declared it a national treasure, triggering a 30-month export ban and effectively pulling it off the market. That kind of intervention is rare but not unheard of in France, where the state can halt sales to give local institutions time to raise funds and keep important works in the country. In this case, the stakes are unusually high. Baldung drawings almost never come up for sale, and this one is being billed as the only surviving silverpoint portrait by the artist still in private hands.…