Here may be another option: could you transport the entire vehicle to Diesel Bob, located near Manchester, if that is not too far from you?
http://dieselbob.co.uk/index.aspx
They are well known around the world, even here in the US, as especially good experts in diesel injection pump overhaul -- and they also appear to offer full vehicle service if you can get the vehicle to them.
No doubt they would be able to successfully handle the resealing/rebuilding of the injection pump AND also the work of removing it and properly reinstalling it on the car, removing any question marks for you.