One way to do this would be to log in to the web or Windows client as the public access account and run a search for all documents.  That list will be all of the documents that account has access to.  You can then export a "metadata report" for that listing, and include the Name and Entry ID.  The entry id is what differentiates different urls.  The only trouble you might run into is that access to the entry id is controlled by the "Extended Properties" feature right, which your WebLink user likely doesn't have.