Welcome to the forum! I do have a lid, it's not a hard shell but a stiff latex one piece, made by a member here, his info is in my build thread (link in my sig). There are also a few threads of people that have done it as a pep file (another member here makes the file) . Next to the search bar at the top of the page is an option for advanced search (+) try searching Big Daddy in the titles only and you should find it.
http://www.therpf.com/attachment.php?attachmentid=318373&d=1398871439
Haven't read 3 yet, I'm waiting for the hard cover edition. :cool