Hi Lynda,
I do apologise - I've got the most undisciplined mind in the world; I get side-tracked very easily when I run across a name or place that I think is familiar. It sometimes leads to a remote family connection or, more often, spends weeks following a paper trail to nowhere. I thoroughly enjoy the journey but am mostly disappointed with the results. I also tend to forget that other people don't have all day and every day to meander around their family research. So, if I say that I'm going to post back and it looks as if I've forgotten then, please, give me a (figurative) nudge to remind me!

Back to the burials:
David LANGDON, of Pentrechwyth, buried at Llansamlet 27 Feb 1886; age 60. The age and place tie in with this being the son of William and Rachel.
According to FreeBMD, David LANGDON married Ann DANIEL 4Q 1858 Neath 11a 644. I had a choice of Ann DANIEL or Catherine DAVIES; I finally picked Ann because an Ann LANGDON, of Foxhole, was buried in Llansamlet 04 Dec 1869; age 43. This seems to tally - right area and age and the 1871 census shows David to be a widower. There is no death registered for a Catherine LANGDON in the right time-frame.
The death of a Rachel LANGDON was registered (FreeBMD again) 3Q 1871 Neath 11a 301; age 12. There was a daughter, 12 year-old Rachel LANGDON, living with widower David in the 1871 census. This also tallies with a burial on 27 Aug 1871 of a Rachel LANGDON, of Pentrechwyth, at Llansamlet; the age in the burial index is, however, given as 13M. There appears to be no Rachel LANGDON birth listed anywhere in England & Wales in 1870.
.... and there's more to come!
Regards,
Lee.