Webwork - 1:39 pm on Jan 3, 2011 (gmt 0)
Looks like you either auction it off "as is" or find a way to srcape its contents into a database version of the directory, one that maintains the same URL structure, and then extract the bad links. That latter idea sounds like work, the ROI of which only you can best project. You might need/want to outsource the "manual labor" to get a better return.
When it comes to making money online diversification of income streams is gospel, so I'd consider keeping it if you can repair the situation to profitability with aff links, contextual ads, listings, etc.