Get yourself a lawyer, the road is difficult and needlessly complex, the owners will not part with money unless all the documentation is presented.It is not just a matter of x rays as the use of asbestos in everyday materials, paving stones, brake linings, mean that city dwellers often carry asbestos fibres in their lungs.It is the quantity, the damage done by exposure, the duration of exposure, the boats worked on, the type of work carried out etc etc .A Solicitor will be your first stop, best wishes.