Your findings on Catherine & Thomas sound very close. Catherine's brother was born in 1859 & your findings show her born about 1862. Sounds close to me. Anyway you can email me that census & marriage? I found an 1881 census that shows David, Alice & their daughter Mary living in Pontypridd, Ystradyfodwg. That is the only census I was able to find for the whole family. Your findings help out tremendously!