Well they had 428 (currently in Dunsandle), 430 (which they soon cut up), the mighty 613, their CSET Ruston 148DS (damaged in a fire in 1990 that destroyed 3205 and 1923, cut up after in 2005 90's salvation and the removal of the rest of the other stock in 2004), and of course, 90, aquired from Mallow in 1987 and running on the mainline by September 1990, which is currently at Downpatrick along with 613. They also had MGWR steam crane 3M (Broadstone?) that I assume was cut up around the same time as the Ruston.
I believe the only items of non-loco stock that survive are composite corridor 2159, (I think) a beet wagon, and the remains of a brake van and a tank wagon at Dunsandle. As well as this, GSWR plough 8472 is at Downpatrick as well.
They had their own livery which was used on 613, 428, and I think the Ruston in the beginning - maroon all over with cream pick-outs and stripes (and lining? On the Ruston anyway, if it did carry it) - as well as, "Overhead Wires," warning stickers.
Some of their coaches were turned out in their own fantastic livery too - the same maroon with cream window surrounds, which went to all-red to cover brake compartments, like on 3205 (tailboard were diagonally striped black/white) It'd be great if 2159 carried it.
One or two of their green coaches had full yellow ends too - not as attractive, really
Sorry, someone else can inform you better on coaches and dates!