Caveat: Just my opinion
The big question is how many cash buyers are there for your van?
In order to compete I tend to take a view that if I want to sell a vehicle, I really put my foot down and make it one of the cheapest out there. With that in mind I would probably list at around £55k ish and be prepared to accept a small offer.
Your first offer is likely to be the best offer you get, usually this person is the most motivated and is chasing the right vehicle.
Whatever you do get offered, before you reject anything ask yourself "would I buy it for that?" because by rejecting any offer, you are effectively buying it once again for the price offered.
You can use this method to help arrive at an attractive selling price as well.
There is no harm in going fishing with a price you have arrived at and then reduce your price down in the next couple of weeks or so. Just be careful not to run the summer clock down too far.
In the end
you have to make the decision, I hate to think that my personal view (or the view of the people on the forum) looses you a grand or three!!
Good luck with it!