A 10 year old van will not be worth repairing from an insurance point of view.
They will scrap it, give you a value of around £750 less your access if you are lucky. They will want to replace all panels with new. It will then be classed as a claim. No matter what they tell you with regard to your no claims discount being protected, it will reflect in the costing of your next premiums. They just load the premium before no claims discount. Also consider that just because you have valued it at £2000 doesn't mean they will pay that out for it.
In the motor trade we would sell a supplementary insurance to cover the difference between what you bought it for and what the insurance company would pay out in an accident. It was called GAP insurance. It was especially important if you bought an older van on HP.
If the van is worth more to you than it is to the insurance company and doesn't cost that much to repair, albeit not perfectly, then pay for it out of your pocket and don't involve insurance. Don't even talk to them about it.
Remember in the eye's of the insurance company there is a difference between having an accident and not claiming for an accident you have had.