After an exasperated, final shake of his steel-tipped ceremonial walking cane at Soviet bureaucrats, Charlie Puka yesterday signed what he saw as the last useless piece of paper imprisoning him here and took off for America - more than a year after he arrived on what was to be a brief visit with his sister.

To the end, the Soviets who had detained the 89-year-old former Pennsylvania coalminer, claiming he was a Soviet citizen and not a naturalized American, carried out their role of bureaucratic heavies.

Puka had spent the night at Sheremetyevo Airport, the pockets of his aging overcoat stuffed with the documents he had fought so long to obtain: a brand new American passport issued that day, an exit visa from the Russians, a currency declaration, and airplane tickets.

"I'm goin' home to America!" he had announced to anyone who asked. Seemingly well behind him was the eight months of fighting with the Soviets to force them to admit they had erred when they issued him a Soviet passport in the United States instead of a visa so he could visit his sister in the Ukrainian town of Velyatino, which he had last seen in 1909 when he left to seek his fortune in America.

He also fought to prove they had erred again in confiscating his U.S. passport and by calling him a Soviet citizen.

Now he sat peaceably on a bench, waiting to get a boarding pass for the fligth to New York when two Soviet customs officials walked up, saying, "We must have your passport. You must fill out customs declaration. Where's your passport?"

"Nobody's takin' my passport!" Puka retorted, gripping his cane, "I'm goin' to America!"

The fight was on, with more custom officials, airport officials and American officials, tugging and hauling, and the American passport being snatched from hand to hand while Puka stormed up and down and the Soviets yammered at him. At one point, he brandished in someone's face the special ceremonial cane given him as a going away present by Ukrainian friends, who last had seen him when their town was part of the Transcarpathian region of the Austro-Hungarian Empire.

At last, clutching his U.S. passport, Puka signed the customs declaration and was on his way back to Glassport, Pa., where he has been sergeant-at-arms at the American Legion Hall for the past 30 years.