Once teetering on the edge of bankruptcy and subject of a buyout bidding war during which offers shrank, Restoration Hardware Holdings Inc. is turning into a bonanza for its private-equity owners, the Wall Street Journal reported today. The firms that bought the luxury-home-furnishings retailer in 2008 are on track to make about eight times their initial investment, when including their remaining stock holdings in the company, according to a Wall Street Journal analysis of securities filings. This is a huge return among deals struck in the years leading up to and during the financial crisis. Five years ago, as the housing crash crimped the company's profits, a group led by Connecticut private-equity firms Catterton Partners and Tower Three Partners LLC and the retailer's chief executive took the company private for about $177 million.