Delbanco arrived in London in the early Thirties from Nazi Germany. His was an old Venetian Jewish trading family which had come to Hamburg in the 19th century. Gustav's father was determined that he should join the family firm of importers and exporters but "G" was equally determined not to. He took a doctorate at Heidelberg and not long afterwards left Germany.
From a small gallery in Piccadilly, Delbanco established himself as possessing one of the finest "eyes" in the country. His expertise was the 17th and 18th centuries and he was often called in by those holding great collections such as the British Museum to help in their evaluations. A Gustav Delbanco authentication was much prized.
After the Second World War he and two partners, Henry Roland and Lillian Browse, decided to open a gallery of contemporary art in Cork Street. Cork Street is now one of the art thoroughfares of Europe, but in 1945 there was only one other gallery there, the Redfern. The only surviving partner of Roland, Browse and Delbanco is Browse, who had set up wartime exhibitions at the National Gallery and met Roland, another Old Master specialist and refugee from Hamburg, when she wanted German lessons.
"In those days all art books were in German," she says, "and so German was an essential language. Neither Gustav nor Henry Roland had much money so they had to do things like give German lessons. But they were widely accepted as men of quite remarkable knowledge."
Roland, Browse and Delbanco, though never one of London's richest galleries, soon became one of its most prestigious. One of their first exhibitions was of Rodin, whose work had suffered considerable neglect in Britain. Painters such as Josef Herman, Philip Sutton, Alfred Cohen, Keith Grant and Bernard Dunstan regularly showed at a gallery which became known as "The Scholars" or "The Connoisseurs".
Delbanco was as interested in people as in paintings. Visitors to the gallery would find themselves engrossed for hours in conversation with him. His wife Stefanie would receive a telephone call saying that he was bringing an extra two or three home to dinner - people he had met in the gallery that afternoon. Occasionally this led to unfortunate misunderstandings.
Painters he met assumed that an invitation to supper implied that the dealer was interested and might show their paintings, when all too often he was fascinated by them, not their work. He looked baffled when it was explained that for a dealer to take home that night a young artist who had come into the gallery to show his work could lead to cruel disappointment. "A bad painter can be an amusing person too," he would reply, simply.
His house in Hampstead was a treasure-store of his eclectic tastes. A splendid Rubens, The Fall of Satan, hung in the drawing-room. He said that in the early days he and Roland frequently "popped" the Rubens when they needed cash. There were wonderful Rodin figurines, a beautiful Degas sculpture of a dancer. "Compare it to a Rodin," he would say, tossing a valuable piece of sculpture. "Do you see that the Degas is cold - a bit lifeless. You see, Degas didn't like women. Rodin did."
Delbanco loved primitive art too. He possessed one of the finest collections in private hands of Staffordshire figures, which he regarded as folk art. Old Master drawings of great value jostled with pieces he had picked up in small salerooms or on his many trips abroad. His house was far too large for him, especially after his wife's death of cancer eight years ago. But he regarded it not so much as a home as a place to display his art, which he re-arranged from time to time "so that I can see it all anew". There were few concessions to modern tastes - a black-and-white television which he never switched on; no central heating. It was his private gallery and he wanted it that way.
Gustav Delbanco was a genuinely modest man who refused to accept that he made any contribution to the fine arts in Britain at all. A great scholar, he refused to write books: "Who cares what I say?"
Gustav Delbanco, art dealer: born Hamburg, Germany 7 December 1903; married 1931 Stefanie Feinberg (died 1988; one daughter); died London 25 January 1997.