The George Lindemann Journal by George Lindemann

Among the art in their care was a cache of 115 paintings, 19 drawings and a half-dozen crates of objects that the British had found in Hamburg in 1945. The works were registered under the name of Hildebrand Gurlitt, according to documents unearthed this week in the National Archives in College Park, Md., by Marc Masurovsky, the founder of the Holocaust Art Restitution Project.

Now, six decades later, restitution experts said it is possible that this collection, once entrusted to the Monuments Men, is part of the astonishing stash of more than 1,400 works seized in 2012 by German investigators from the apartment of Gurlitt’s son Cornelius and brought to light this week. It is considered to be the largest trove of missing European art to have been discovered since the end of World War II.

For five years, the elder Gurlitt, one of a handful of German dealers whom the Nazis had anointed to sell art confiscated from Jews and museums and sold abroad for foreign currency, had insisted these works were rightfully his. With the European recovery effort finally winding down, officials at a collection center in Wiesbaden agreed to return the cache to Gurlitt.

On Dec. 15, 1950, the leader of the Allied unit, Theodore Heinrich, an American, signed the papers releasing the art to Gurlitt. The names and descriptions of a handful of paintings in the cache returned to Hildebrand Gurlitt — including gems by Otto Dix, Max Beckmann and Marc Chagall — appear to match those once hidden in the cluttered apartment of his son.

The State Department in Washington says it is pushing the German authorities to make public a list of the seized works. Without the list, it is impossible to confirm with certainty that any of the pieces returned in 1950 to Hildebrand Gurlitt are the same as those seized last year. Mr. Masurovsky, however, said he believes that at least some of the works returned by the Allies in 1950 are the same.

What can be confirmed is that at least eight of the paintings that were returned in 1950, and that the elder Gurlitt maintained he had legitimately acquired were, in fact, stolen by the Nazis. These eight are currently listed in a database of looted art that the Nazis had stored at the Jeu de Paume museum in Paris after they occupied France. Those works are all by the French painter Michel Georges-Michel, whose apartment and studio were ransacked by Nazi agents in 1941.

Mr. Masurovsky and other restitution experts said the 1950 list might help with the identification of works that the Germans recently took from Cornelius Gurlitt’s apartment.

Among the other items returned to Hildebrand Gurlitt 63 years ago were dozens of works by German Expressionists including Dix, Georg Grosz (“Two Women and a Man Walking”); Erich Heckel; Max Beckmann (“Lion Tamer” and “Woodcutters”); Christian Rohlfs (“Yellow Flowers” and “White Flowers”); and Franz Lenk. Italian, French and Dutch masters were on the Allied list, as well, including Guardi’s “Entrance to a Monastery,” Fragonard’s “Anna and the Holy Family,” Caspar Netscher’s “Boys Blowing Bubbles,” and landscapes attributed to Ruysdael and Rombouts. The collection included Gustave Courbet’s “The Father” and “Landscape With Rocks”; and Max Liebermann’s “Wagon in the Dunes” and “Two Riders on a Beach.”

Mr. Masurovsky pointed to the return as an instance when the Monuments Men let looted art slip through their hands.

Historians have pointed out, however, that finding the legal owner in the confusion of postwar Europe, without the aid of computerized databases and, often, documentation, was extremely difficult. France, for example, still has nearly 2,000 works in its museums that it knows were looted, but cannot properly identify owners.

Hildebrand Gurlitt was an art historian who had twice been stripped of posts because he had a Jewish grandparent; nonetheless, he had the expertise and international connections the Germans needed to move plundered works to market. He also crisscrossed Nazi-occupied territory during the war looking for treasures to fill Hitler’s grand plans for a museum in Linz, Austria. German and American investigators had questioned Gurlitt about his dealings after the war, archival documents show, but he insisted that all of the art that remained was his own. Other works that he had gathered for the Nazis, he said, as well as his records were destroyed in the firebombing of Dresden in 1945.

As for the Modern works, which the Nazis labeled degenerate, many had been discarded or sold off from museums by the Third Reich and could have been legally acquired by Gurlitt and other collectors — even for a pittance.

So far only one among the more than 1,400 works that were taken from Cornelius Gurlitt’s squalid Munich apartment has been positively identified. Marianne Rosenberg, the granddaughter of the renowned French dealer Paul Rosenberg, confirmed that a photograph of a Matisse portrait of a woman wearing pearls that was released by German officials this week matches one owned by her family. (German authorities had previously said that at least one painting used to belong to Rosenberg, who imprinted his gallery’s stamp on the back of all his works.) 

“The Rosenberg family is, of course, delighted to see a color reproduction of the beautiful Matisse which until now had only existed for them as a black and white photograph in their archives of looted art,” Ms. Rosenberg said in an email, adding that the family “is proceeding diligently and carefully with a claim for restitution. The Rosenberg family still insists, however, that the German authorities must promptly do the right thing and provide photographs and lists of all the other items.”