Jawfin, 907 is listed as a 30ft 1st / 2nd composite, built in 1889 by the Waterford & Limerick, and obviously absorbed into the GSWR in 1901. However, there's no drawing. It was gas lit and had 16 first class seats and 20 second class. That would be two first class compartments and two second. There's no mention of a loo in between. Being of W & L origin, it probably had curved in ends - the W & L was the only Irish company to do this, though such features were a lot more common in Britain.
This coach is listed among 42 of the type. 906, 907 and 909 were ex-W & L, whereas the rest were GSWR built (in Inchicore, of course). All were gas lit except 517, 518 & 520 (GSWR type) which were oil lit.
They were all built between 1879 and 1893.