Here's the final chapter on this.
First I've nipped the material around the passenger seat back to add a bit more tension, using two fasteners together.

The half-half tonneau cover which goes from the hood cover to the windstop needed more help to stay in place. This is how - a short drop fastener (made with Mohair/Twillfast) from one of the existing studs.......
Here it's pulled rearwards so you can see it. All this is, is a short length of Mohair - double width. It's folded in half lengthways over double sided tape and pressed in the vice. Once the holes are punched and the fasteners fitted, that's it.....

And here it is in place properly:

I must say that working with hood material is very relaxing. Maybe I should look out for an industrial sewing machine....

Ready for when I retire.......