On Aug. 14, 1975, eight daring thieves ransacked 148 massive safe-deposit boxes at a secret bank used by organized crime, La Cosa Nostra, and its associates in Providence, R.I. The crooks fled with duffle bags crammed full of cash, gold, silver, stamps, coins, jewels and high-end jewelry. The true value of the loot has always been kept secret, partly because it was ill-gotten to begin with, and partly because there was plenty of incentive to keep its true worth out of the limelight. It's one thing for authorities to admit they didn't find a trace of goods worth from $3 million to $4 million,...