He had some solid names in his amateur record too ill try dig it up somewhere http://www.boxrec.com/media/index.php/Sven_Ottke's_Amateur_Record Had it on a different site before but this looks the same
Bobby Halpern always springs to my mind. He served 17 years of a 20-year sentence and then returned to the pro game (after three fights as a young man) at 43 and proved a big draw, although he was never world class.
Bonecrusher is a great pick, one of the few men in boxing to get stopped on his pro debut and wind up world champ.
Not sure i dont go off boxrec stats but the commentators said it when he beat enzo and i heard it elsewhere aswell
Matt Skelton, he won british commenwealth and european titles, then challegend for a world title and he was about 95 year old when he started.
paul sykes was 32 and got to a british title fight the following year... and got the beating of his life against john l gardner