A common thing thats done with bikes (which I know quite a lot about writing off) but can be done with cars/vans is that the insurance company write it off and you buy it back.
They say its not worth it, and pay out the value of the van (well, whatever they say the value of the van is), but then you buy the van back from them for peanuts and fix it up, and re-register it. The downside is that the van is forever marked as an ex-write-off, but thats only a potential problem when you come to sell it. So basically you get the money but get to keep the van.
Some insurance do this without any problems, others wont, so ask them if its a possibility.