When Juan Penton took the witness stand this week, he described himself as a Hialeah carpenter who made wooden cigar boxes stamped ''made in Cuba'' to sell as novelty gifts. But on Friday, a dozen Miami federal jurors found him guilty of selling $3,000 worth of counterfeit cigars in those imitation boxes. They concluded he was essentially copying famous Cuban cigar trademarks such as Montecristo, which are registered in the United States by its largest cigar producer. The David-and-Goliath legal tale pitted Penton not only against the U.S. government but also the giant cigar company that funded part of the...