Have you looked at Marco website? He has some nice pictures that show the top installation of a 28 or 29 (same thing). The picture show the steps in installing the top. There is no chicken wire used. I have a 29 CCPU, but I haven't started to restore it yet, but trying to learn as much as I can beforehand. Marco's website is:
http://abarnyard.com/temp/82-a/
Rusty