Identify spoons

[joho]

Hi. I have a set of 6 mid 18th century table spoons and I am trying to identify where and by whom they were made. 5 are stamped twice by maker IN (or possibly NI) and the 6th is stamped twice by maker GN. There are no other marks. They are of typical hanovarian pattern and I believe could be provincial or colonial. I acquired them about 10 years ago and the seller thought they might be Irish. Would be grateful for any help. Many thanks John