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I (quick port) all L4D1 campaigns as a courtesy. This means they still have any model / texture / or other issues they had originally, but should be playable on L4D2.  I hope to be able to fix some of them completely at some point.  Some have been posted on the Steam Workshop under username TimelordMagnums357.  Feel free to send any testing notes, comments, or porting suggestions to my email address below. Working to keep the game alive. 
Greensboro, NC
United States of America