[Chevelle-List] 64 Convertible question

[gm2]

My 64 Convertible has fabric that has fallen down between the trunk and the cabin of the car.  Right now, the fabric is hanging down into the trunk area and you can see right into the trunk when looking over the back seat.    Since this car is new to me, I don't know how it attaches to the car the correct way.  Should there be some type of board under the fabric to make it sturdier or will this cause problems when the top is put down.  I want to seal this opening back up to avoid any exhaust fumes that may seep into the trunk area and find its way into the cabin of the car.  Can anyone tell me how this should be fixed?   Thanks,   Gary