Bryan,
Andrew Ross in Mullaghboy in the 2 censuses, married Jane McCammon in 1863. (Registered Larne Volume 6, page 489). His father?s name was John. If you order a copy of that marriage cert, you may be able to get more information about whether it?s the correct John (eg townland, father?s occupation etc).
You can order a photocopy from GRO Roscommon for ?4 per certificate. Put the place, year, quarter (where there is one), volume & page number on the application form (anywhere). Don?t worry about leaving some boxes blank. You don?t need to fill them all in if you have the reference details. http://www.groireland.ie/ You have to post or fax the form to them but they will e-mail the copy certificate to you if you wish. Tick the relevant box on the form.
Incidentally, you may have noticed that Andrew remarried c 1903. His second wife?s name was also Ross, so a cousin perhaps?
The Ross family in the census were Presbyterian. There are 2 churches that they are likely to have attended. Islandmagee 1st Presbyterian Church?s records start in 1829, and the 2nd in 1848 for marriages and 1854 for baptisms. Copies of both sets of records are held in PRONI (the public record office) in Belfast. They are not on-line anywhere so far as I am aware. However you will see from the dates that they are unlikely to contain John Ross?s first marriage and won?t have details of his baptism and parents. You might get the information from some other source eg a gravestone or will but probably not from church records.
Here?s the abstracts (summaries) of 2 wills that may relate to your family. Both died intestate, but their probate files will be in PRONI.
Full Abstract :
Ross John of Mullaghboy Islandmagee county Antrim farmer died 5 May 1931 Administration Belfast 5 June to Jennie Ross spinster. Effects ?1092 4s. 6d.
Full Abstract :
Ross Mary of Mullaghboy Islandmagee county Antrim widow died 12 February 1939 Administration Belfast 26 July to Adam Alexander Ross cashier. Effects ?407 15s.
5 people named Ross from Mullaghboy signed the Ulster Covenant in 1912. If you want to see their signatures etc, follow this link:
http://applications.proni.gov.uk/UlsterCovenant/SearchResults.aspx
Griffiths Valuation in 1861 has two Ross households in Mullaghboy. One was John Ross with a house on plot 17c; the other Samuel Ross with a farmhouse, outbuildings and 11 acres of land on plot 6.
http://www.askaboutireland.ie/griffith-valuation/index.xml
You can follow through and see when they died or left and who replaced them using the revaluation books which go up to 1929.
http://www.proni.gov.uk/index/search_the_archives/val12b.htm
Elwyn