The listings give details of the locations (Web Site Locations) for a particular model. They may not detail the actual originator of that model, unless that model is still in it's original form. The readme files should give a full history of the model concerned, including the originator of the 3DZ files.
NOTE: The cockpits listed are available as seperate downloads. Some aircraft cockpits are not listed as they are an integral part of the aircraft download. If you cannot find a particular cockpit, try downloading the aircraft zip - the cockpit may be in there.