Hi David, I also was born in Edinburgh but now live in Canada. My ancestry is predominantly from East Lothian. Gladsmuir,Tranent,Aberlady etc. If you e-mail me at firstname.lastname@example.org
with the names and dates of your 1855 Ancestors I will check against my research and advise. I can also recommend a Genealogy site for the Midlothian,East Lothian and Borders areas where you can post your enquiries. I have found it most helpful.
Andrew Sibbald Ontario Canada