We have just bought an Isabella Air X-tension, with an Isabella modified California uk tunnel.

Can I ask if there is anything we should know about fitting the tunnel i.e. regarding the cuts in the kedar? which is the Isabella mod for the Eriba.

I found with mine (as supplied to fit a VW campervan) that the sides of the tunnel where it joined the Eriba were not even.
I therefore made a small cut in the kedar strip to allow the side to drop slightly, that allowed for better shaping when pegging out and tensioning the tunnel.

Thank you GrandpaP, I think I know what you mean.
So the cut bit doesn't go in the awning rail.

I have a couple of pictures you may find useful.
If you pm me with your mobile I will send them via whattsap.