Wow. I kind of wasn't expecting this to have blown up like it did.
Unfortunately, I know nothing about Wales as no one else in my family tree comes from there.
The Llewellyn mentioned moved to Ireland, then left Ireland for America, got married and had one child then moved back to Ireland where he died. The Welsh connection is a bit of a loss to me.
The only record I have to connect is this:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Belfast_East/Alexander/143250/Which shows him in Clevedon, England. Which lead myself to the record in Bedminister with Mary Ann, him and his other siblings.
The only thing I know about him is that he apparently spoke of a connection to Monmouthshire and that he was a fluent Welsh speaker. All of which is pretty unreliable information.
I will have to take a look at these records. I am not hugely familiar with where to find Welsh records as I am based in Ireland but I will take a look at the references you have provided.
Also, yes the Helbyon is Llewellyn. It's a particularly poor interpretation - though I couldn't read the place names!
The record I referred to and snipped that from was the one showing them at 1 Slade Road, Portishead.
Many thanks everyone for the help.