Jacques Cassandri, who was convicted of extortion, pimping and drug trafficking after the dismantling of part of the French Connection drug-smuggling network in the 1970s, claimed to have been the brains behind the raid in his memoirs published in 2010.
But in court last month he said the claim was an empty boast.
In what was dubbed the "bank job of the century" at the time, thieves dug a tunnel under the Nice branch of the Société Générale bank, even installing hundreds of metres of electrical cable to provide lighting, and made off with 46 million francs (27 million euros) stolen from about 300 safes.
Crime historians have generally attributed the planning to Albert Spaggiari, who died in 1976.
But in 2010 Cassandri claimed he was the real Mr Big, prompting investigators to search for some of the proceeds in his various and complex business interests.
Prosecutor Etienne Perrin told the court that there was corroborating evidence indicating Cassandri's involvement and called for a five-year prison sentence and 300,000-euro fine.
But he was finally convicted of lesser offences and given a 200,000-euro fine and 30-month sentence.
Having already served six months in preventive detention, he is unlikely to serve any more time behind bars.
One of the convictions involved an Irish connection - an agreement that Irish estate agent Paul Blanchfield would pay Cassandri up to a million euros to obtain permission to build tourist accommodation in the Corsican district of Conca, partly in an area that was liable to flooding.
Blanchfield in court denied he was a victim of racketeering in court, saying that the sum of 65,000 euros that was finally paid was an "entry ticket".
Conca mayor François Mosconi was given a two-year suspended sentence and 200,000-euro fine and banned from holding public office for five years for his role in the affair.
Four of Cassandri's family were also convicted.
His wife, Marianne, was given a two-year suspended sentence, his son Antoine 12-months suspended, his daughter Jennifer two years suspended, and Antoine's wife, Vanessa, 18 months suspended for various crimes including misuse of company assets and fraud.
But a prosecution bid to close the Son des Guitares bar for three years failed.
At the age of 74, Marianne Cassandri works at the bar, outside which off-duty police officer Claude Da Luz shot dead a young man who was allegedly illegally employed to provide security there in January in an exchange of fire.