Just an update...Catterick Caravans handling of this situation has been fantastic and I cannot recommend these people highly enough. Many thanks to them for their help.
They have exchanged the awning for a size smaller...haven't had time to try it on the van yet.
Since this episode I have been made aware of the website of Walker awnings and their method of determining the awning size for a caravan with a severely sloping aerodynamic front
My awning rail length is 968 which suggests an awning size of 975
Walkers method gives me a measurement of 951 which suggests an awning size of 950
I have attached a link to Walker's measurement method below
Edited by Hobbynut, 20 July 2013 - 02:50 PM.