Have solved the problem,
The water pump fitted previously was not the right one as it had around 4 to 5 mm gap between the pump and the thermostat housing and a new one sourced from the UK which has a gap less than 1mm, it also came with a special "O" ring ( a little larger than the Land Rover one) I also managed to find the copper ring from the series 1 shop.
Thanks for all of your help.
Malcolm