I don’t see any Gault families in Taylorstown in Griffiths Valuation for 1862.
He had plot 5 which was a small farm (three quarters of an acre). What was William’s occupation, as per the marriage certificate?
http://www.askaboutireland.ie/griffith-valuation/index.xml
I see this family in 1901:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Ballyscullion/Gillistown/941375/
Also:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Ballyscullion/Gillistown/941349/
They were Presbyterian. Were your family Presbyterian? Grange Presbyterian church is probably the nearest to where they lived. Their baptism and marriage records start in 1824. It might be worth checking them to see if your family attended that church. There’s a copy in PRONI (the public record office) in Belfast. I don’t think they are available on-line anywhere though.
The gravestone inscriptions for Grange are on-line. I don’t see any Gault graves, but that’s not too unusual. Many people were buried without a gravestone.
Probate abstracts for the Gillistown Gaults:
Probate of the Will of William Gault late of Gillistown County Antrim Farmer who died 21 June 1911 granted at Belfast to William Samuel Rainey and Archibald Montgomery Farmers.
Gault Adeline of Gillistown Ahoghill county Antrim died 29 April 1944 Administration Belfast 20 October to Robert Gault farmer the husband. Effects £663 10s. 4d.
Gault Robert of Gillistown Ahoghill county Antrim farmer died 8 December 1947 Probate Belfast 10 February to Robert Gault farmer Annie Stewart married woman and John McCullough farmer. Effects £1183 18s. 4d.