They aren't much to look at, Customs Commissioner Carol B. Hallett was quick to concede.

They are old, faded and so heavily canceled that many of the designs are difficult to see. "They're not the colorful stamps that collectors like," Hallett said yesterday.

Yet for 45 years the eight stamps Hallett was holding in a thick glass frame have been the subject of mystery and a three-party international dispute.

The stamps, among the first produced in the world, come from governments that no longer exist: the former British possessions of Mauritius and British Guiana and the independent Hawaiian Islands. They were secreted out of Berlin's Reichspostmuseum in 1945 as Allied bombing raids were destroying many of the city's buildings. The stamps were hidden in their original lead frame, along with gold and other valuables, in a salt mine in Saxony, in what became East Germany, before being taken to the United States.

Said to be among the most valuable stamps in the world, they have been held for the past 14 years in a Customs vault in Philadelphia as both East and West Germany fought with the State Department over which government could claim them.

"We expect {the} investigation to be a lengthy process," then-Secretary of State Cyrus Vance cabled the two countries in 1978 after their claims had been presented. Unable to resolve the dispute quickly, officials in Foggy Bottom insisted the stamps, now valued at at least $1.1 million, remain in the vault.

The State Department rejected an overture from the Smithsonian Institution to display the stamps temporarily in its collection and another from the late Sen. Spark Matsunaga (D-Hawaii) to return the four valuable Hawaiian stamps to a stamp society in his state.

"The decision as to whether the Federal Republic of Germany or the Democratic Republic of Germany, or both, shall be considered the present owner or owners involves sensitive questions and the department is still considering what may be properly done in the matter," a State Department official told a stamp publication in 1987, a decade after the stamps were seized.

With the unification of Germany earlier this month, that all changed, Hallett said. The Customs Service arranged within three weeks to return the stamps.

This afternoon, over toasts of German champagne, Hallett will conclude one aspect of the stamps' saga, returning them to German Ambassador Juergen Ruhfus. "Now this will be part of the celebration of unification," she said.

But the other part of the story -- how a cache of priceless stamps from a German museum ended up in the hands of the U.S. government -- will probably go unanswered, the commissioner said.

In 1976 Dennis E. Sweeney, a former Army captain from Reading, Pa., showed up at an international stamp show in Philadelphia and offered to sell the frame with all eight stamps to Robson Lowe, a dealer from London. Lowe immediately recognized the stamps as extremely valuable and suspected they were stolen. When he returned to London he notified Scotland Yard, which in turn contacted Interpol, the international police agency.

Interpol verified that the stamps were indeed among those missing from the Reichspostmuseum collection and asked U.S. Customs officials to intervene. Somehow (Customs officials won't say how) Sweeney was persuaded to "voluntarily surrender" the stamps and Customs agents confiscated them in 1977 as stolen property. Customs officials investigated the case for years without bringing any charges against him.

Hallett said the former serviceman told investigators he had been with the liberating armies in eastern Germany. When the soldier's unit was pulled out of the area in 1945, she said, an elderly couple with whom he had stayed presented him with the stamps, "partly as a gift."

The stamps remained in the soldier's attic in Reading for 32 years until he decided to take them to the stamp show, Hallett said.

How did Sweeney get the stamps? Did the government believe his account?

The commissioner smiled. "We have to assume that the elderly couple and the soldier knew a lot more than I do, but they are all dead, so we don't know," she said.

Sweeney died in 1980. Customs officials said they doubted that his heirs will be able to claim a $50,000 reward that the West German government offered for the return of the stamps.

Customs officials said the new German government now faces yet another dilemma regarding the stamps. With unification, Germany has two postal museums, one in Frankfurt and another in Berlin, and the government will have to make the final decision as to where the stamps go, said one official.