I am searching for my Gunter ancestors too.
From a family bible I have the birth of Ann Gunter July 1848.
I also have her marriage certificate to Samuel Williams 16th May 1871 Nantyglo MON, which puts her year of birth at 1847/48, her father's name on the certificate is William Gunter.
From the 1881/1891 census Ann was born in Llangattock BRE but I cannot find a Ann Gunter on the previous census with a father William Gunter. The only likely one is 1851 but her age on that would give a birth of 1841/42
Any help or comments gratefully received