I don't remember for this one but when I sometimes extract new add-ons into the OFP add-on folder, it places a new folder for that add-on that wont allow me to find it in the editor.
I have to go back out to the game add-on folder... find the new subdirectory folder that was created and remove the file and place it directly into the OFP add-on folder.
See if it is true for this add-on...
IW