You can contact the Diocese Office in Colombo to get Birth/Marriage/Death information as far back as 1800's, if the.I have lost contacts with them,but if you do a good google search, you'll find their contacts. I have found a church near the office, The Church of The Good Shepherd in Thimbirigasyaya, whose contacts are Tel.(94)-11-2585889 E-mail: email@example.com . They'll find you the Diocese office number/email. The Dioocese secretary is a very nice person who is always there to help.