Mike,
I had a look at the marriage records 1911 – 1931 to see if I could spot a marriage for Samuel. There are about 35 marriages for people of that name, none in Ballymoney (the registration area Moneysallin is in). Of course tradition is to marry in the bride’s church so if he married someone from another area it could be any of those marriages. It will cost you £2 (pounds sterling) to view each of those certificates on the GRONI website. That’s one way of searching for him, but it’s a bit of a needle in haystack. And he mightn't have married at all, or he might have married somewhere outside Ireland.
His age means that he’s quite likely to have volunteered for service in WW1. I checked the war dead on the CWGC site. There are quite a few Samuel Gibsons listed there. Some with parents names, some not. I saw this one with no age and no parents that might fit:
http://www.cwgc.org/find-war-dead/casualty/839859/GIBSON,%20SAMUEL
Likewise with military service records, there are numerous Samuel Gibsons but also dozens of S. Gibsons. Too many too sort through.
I searched for Samuel Joseph’s birth but could not find it. I did note Sarah, regd Coleraine 7th June 1897, mothers maiden name Furlong. Matilda regd there 6.6.1899 mother’s maiden name Furlow.
With such a common name, trying to find what happened to him after 1911 is very difficult. I am afraid that without a bit more information about what career he might have pursued etc, it’s extremely difficult to trace him. I have one possible clue for you though. I had a look for Simon, Anthony Joseph’s brother. I couldn’t see a marriage for him either, up to 1935. But I noted this probate abstract:
Gibson, Simon Joseph of Killygullib Kilrea county Londonderry retired farmer died 19 March 1968 Probate Belfast 6 August to George Arthur McIlrath farmer and auctioneer and John Johnston McClenahan farmer. Effects £1200.
http://apps.proni.gov.uk/DCAL_PRONI_WillsCalendar_IE/willsSearchResultsDetails.aspx
Now here’s the Gibson farm in 1911:
http://www.census.nationalarchives.ie/pages/1911/Londonderry/Hervey_Hill/Killygullib_Glebe/591755/
You’ll notice that it included Sarah & Matilda, from your family, who were not with their parents in Moneysallin on census night. So there’s some significant connection between these two farms. So possibly the Simon who died there in 1968 is "your" Simon who inherited it or bought it. You might want to get a copy of his will from PRONI to see what next of kin he named in it. (Killygullib is immediately adjacent to Moneysallin. The two farms were very close together). I can see from the current phone book that a G. Gibson still lives in Killygullib, so you might want to contact them. I can't give you the full details due to our site's privacy reasons relating to living people but you should be able to locate the household easily enough on: http://www.ukphonebook.com