Can't say that I have made much progress, but a couple of interesting points have arisen.
Joseph is noted on the 1861 Census as being born in Norfolk, and being a greengrocer in Cwmdare, Aberdare. In the 1871 Census (where they continue to be elusive), a Susan Pike, widow aged 49 from Norfolk is living in Cwmdare, Aberdare and working as a greengrocer.
Secondly, Emily is described in the 1881 census as being 14 and born in Cardiff, but I can't find her birth on the complete BMD at that time. More research needed here I suspect.
The written detail on the 1881 census is so poor, that you can understand how complete families just disappear !