pumkinpilot
You are making life hard for yourself.
Contact Michael Whitley at Cambrai covers and he will modify the cover for you.
Cambrai are located at Langtoft about a mile down the road from Eddsfield airstrip in Yorkshire. Fly in, meet Michael and discuss. I have done this a couple of times when I wanted covers modified/cleaned etc.
http://www.cambraicovers.com/