Thomas and Emma WILLIAMS possibly of Caerhun

[Helig]

These days I am the same and tend to use Ancestry and Find my Past.

It doesn't look as though the baptisms in Llanwrst in the 1760s and 1770s are on Freereg.

Brynsyllty appears to be a hamlet outside Llanwrst. Google the place name and a number of results come up for it.

Trying to find out more information on the two burials pre registration is going to be tricky. I doubt you will be able to determine the Thomas Williams who is your ancestor with any certainty. At best it will be a possible, or possibles, for him.