Hi Chris and welcome to the World of Hunter Campers.
In my 1973 Hunter Compact-II the top boot is 4 pieces of material. all about 14 inches wide. The front & back pieces are 29", the sides are 62 inches and it is all sewn up into one piece. The bottom edge is attached to the vertical walls of the hatch opening with 10-32 screws about every 12 inches, the top edge is fastened on the same way through the top, look and you will see the holes.
It has about a 1" hem top and bottom for reinforcement.
Best bet is to see one that is intact. I may be in Vegas with mine late in June if that's of any help.
or tent shop can knock out one for you for about $300-$400, including screens and covers for the openings.
You might also start a new thread with your question, otherwise it might not be seen here.