Thanks for that, it's actually very helpful.
I suspected Cefn Mawr, but my knowledge of the geography isn't the best. I also know of the Llangollen Canal, and have a DNA Match on what I suspect is this line, with a person with ancestry in that exact area.
The registration district for there seems to be Corwen, and I have a certificate for someone born in Corwen in 1855, but it raises more questions than it answers.
This one is proving incredibly difficult because of the movement and the lack of consistency with the spellings. The ages are varying somewhat as well which also isn't helping...