The following is in reply to a request in the Galbraith forum, posted here in the hopes it is helpful to someone else.
Extract from Gravestone Inscriptions of County Down volume 20, R.S.J.Clarke, Belfast 1989:
page 42 Banbridge, Scarva Street Presbyterian Graveyard CATHCART [White Limestone in surround in a high stone-and-rail enclosure.]The family burying place of Robert Cathcart.Erected 1869 to the memory of his three children: Robt. William aged 2 yr & 5 mos.; Mary Alexandra ages 10 mos.; Florence Caroline aged 4 yr. & 9 mos.Also his son James who died 16th Septr. 1870 aged 21 years.Also the above named Robert Cathcart who died 28th May 1876 aged 65 years.Also his daughters: Elizabeth who died 24th April 1879; and Alice Amelia who died 11th June 1879.Also Eleanor Harriett, beloved wife of Robert Cathcart, who died 26th March 1883 aged 58 years.Also Eleanor Cathcart who died 19th March 1923 aged 75 years. [The will of Robert Cathcart, late of Banbridge, county Down, merchant, who died 28 May 1876 at the same place, was proved at the Principal Registry 27 June 1876 by the oath of the Reverend John Sinclair Hamilton of Banbridge, the sole executor, Effects under [pounds]100.]
A quick peek in Basset's 1886 Directory of County Down indicates the Presbyterian congregation dates from 1720, previously connected with a congregation of Magherally.The scarva-street church was erected in 1830.