Hi neville
Mine is made for a Vixen. I suggest just taking measurements across your turtledeck opening and then allowing about 2 inches for down the sides. I marked and cut holes to allow the attach points to project through the cover. The slots at the front allow the flapperons to project through. Fix strips of self-adhesive Velcro to the main headache tube and the two flaps on your cover. Sew the Velcro to the flaps.
I could try for dimentions but you may be better off to just "custom fit" it to your aircraft.
The Cordura is very tough and allows holes to be cut without the edges fraying. Although I don`t tow much any more it is handy just for protection if the a/c is stored folded.
Have fun
Don