hi, I only found your post in the last few days, I have a g/g/grandfather named James Hagan born 1818
in Drumcaw Co. Down who married a
Jane Melville born 1822, his father, also James was
married to a Sarah (in Claragh) prior to moving to Drumcaw and having several children, among them was my g/grandfather Moses d.o.b. 1844 who moved to Greenock and married Janet McBride Cunningham who had also several children including my grandfather James Melville Hagan/Hegan (AKA Barney) who moved to Paisley and married my g/mother Margaret Muir Baillie, she died in 1946 while Barney lived till 1953.
try this link
http://inverclyde.gov.uk/community-life-and-leisure/local-history-and-heritage/watt-library-births-marriages-deaths-index