Obviously the ideal will be a Rum Rationer in your area who can lend you one but, failing that, I see that the Caravan Club has a Classified section. I have looked in its 'accessories' for this kind of awning but don't really understand what is on offer - you might. You can place your own ad on there, if you wish. You could ask if a local caravanner might loan one to you in exchange for a small donation to the person's preferred charity. Here you are:
Many thanks for your time Soleil I have been on most of the camping/caravan sites with no success, and RR is probably the last gambit having advertised elsewhere privately. I may trade up the camper as a last resort. I will of course keep you posted, thanks again for your concern.