Scottish records are amazing (me, biased
) but not everything is where we hope
Need to take this back to basics for you. I don't like over posting without responses (feels lonely) so glad that you are there...
On a standard search for someone like William you would look for:
BMDs for the family
Census info - can see 1861 (1851?)
Wills and entries - none show that I can see here
www.scotlandspeople.gov.ukWith Rosie's mention of him being a Chelsea Pensioner, wondered about these military records here at TNA
http://discovery.nationalarchives.gov.uk/details/r/C8786160Son (guess he showed as son he reported father William's death in 1866?) John Arthur Copeland Brittain. In the right place etc. when reporting father's death. Where was he in 1851 and 1861? Master mariner when he married second time around - doesn't help having a mariner often when looking for census entries...
Curious that he remarried in the Chester area in 1877. There is a birth in 1819, or thereabouts, which is covered by a private tree on a/try for a John Arthur Copeland Brittain -
http://trees.ancestry.co.uk/pt/RequestTreeAccess.aspx?tid=75791324&pid=38324893859. Such a specific set of names, wondered whether there was a connection back to William Brittain, but can't tell...
Newspapers and any possible mentions there might also help.
Monica
Added: Other source would be the Post Office Directories or business directories,
www.nls.uk/family-history/directories/post-office/index.cfm?place=Renfrewshire