Hi, I’ve been. Some of the grave stones have numbers on the back. But it’s inconsistent so you can’t just count because it isn’t apparent which direction the numbering goes.
Y ffôr.com’s C section corresponds with the physical grave plot numbers but in cymdeithas hanes teulu gwynedd’s records it’s B section.
I emailed the parish council but I didn’t get a reply. I also visited the monumental stone masons that had their name alongside the plot numbers. They confirmed that the sections ABCD etc are correct but that plot numbers are not always known. They always ask the council but they don’t always get an answer.
The only hope you have is to look at the back of gravestone and if you’re lucky, the grave you’re looking for is nearby.
In my case I was looking for a grave for a Jane Ann Williams which is included in yffor.com’s list but isn’t on cymdeithas hanes teulu gwynedd’s list. I did find a slate with JAW initials on it only about three or four graves from her known parents. I think this is her grave but it would be good to find the source record. Yffor.com couldn’t remember where they got it from!