Hi Rod I am not sure but on this web site he does make mention of where he found all his information so maybe he will tell you there - there were some fantastic prints of old Sunderland bridges and the river - you need to surf about on his site a bit and he would be delighted to receive an email from you if you wish to ask him any questions about where he got copies of his ships etc He replied to me straight away and was very helpful (I am researching Laing shipbuilders) happy hunting Alison