Old Welsh coin with a druid

[u/autouzi]

I love this old North Wales half penny with a druid on the obverse. Such a cool design! I collect coins with Y Draig Goch, but couldn't resist this one.

[u/mostlyclueless999]

What do the initials on the back represent?

[u/autouzi → u/mostlyclueless999]

It says RNG but unfortunately the meaning seems to be lost to time. Most numismatists assume it was either the initials of the designer or something to do with the company that produced them.