I've seen several references online regarding a converted Walker with an extractor port, but do not see a ready made extractor offered. Has anyone went through the process to equip a Walker or Dragoon in such a manner? If so, did you use off-the-shelf components? The link below has what looks like pictures of a converted Dragoon or Walker.
http://gunsoftheoldwest.com/2013/08/guns-of-the-gunfighters-walker-colt-conversion/
http://gunsoftheoldwest.com/2013/08/guns-of-the-gunfighters-walker-colt-conversion/