"Gilfach is the small district that lies between Bargoed and Pengam, situated in the Caerphilly county borough, seven miles north of Caerphilly, within the historic boundaries of Glamorgan." wikipedia
"GILFACH, 2 miles north and adjoining Bargoed om the south, is a growing village, with a halt on the Great Western railway." [From Kelly's South Wales Directory 1923 (ArchiveCDBooks) - transcribed by Gareth Hicks]
The church is dedicated to St. Margaret, is in the Benefice of Gelligaer, and the diocese of Llandaff. Details of the present incumbent of this benefice can be found at the Church in Wales website. The church can be located at grid reference ST151986.
Anglican Parish Registers Held at the Glamorgan Record Office (St. Margaret, Gilfach)
Non Conformist Registers Held at the National Library of Wales, Aberystwyth