Ok great so I think from you said it could be best to let them offer me their write off value (they've said £1450) and then ask to buy it back off them and see what they want from me? I didn't think it'd cost that much to just replace a wing and repair the bumper so not sure why they've said it's a write off at all.
In the first instance they tend to default to the cost of new replacement panels direct from the manufacturer, then fitting and paint by a professional. That all stacks up and when it starts getting anywhere remotely close to their insurance valuation they just deem it simpler to write the car off.
Personally I'd save myself the cost of the excess and source a replacement panel in the same colour for £25-50 as others have said, then either bolt it on yourself or get a local garage to do it for you.
Somewhere like CBS Autos in Colne or any would be a good one stop shop if its not too far, or any decent specialist for that matter - you'll probably be able to source the part and get it fitted at the same time.
Ok thanks for the advice. I don't have an excess don't I don't need to worry about that. I'm getting a call from an engineer today so if I can buy it back at scrap value I probably will just source a part myself and get someone to colour match it and fit it for a fraction of the cost the insurers think it would be.