Welcome to Rootschat, Blueberry!
This thread is 17 years old, and several of the people involved have not logged into RootsChat for several years. If their email address is still active, they should hopefully be notified of your response.
That said, this Arthur was born long before your grandfather's brother. Would you like some help in tracing your grandfather's family history? There are lots of us happy to help with your queries.
I had a quick look for you and it appears, based on what you have said, that this is your great-uncle:
Name: BARNARD, ARTHUR EDWARD Mother's Maiden Name: KERVEY
GRO Reference : 1922 (Year of Birth) D Quarter in WANGFORD (Registration District)
Volume 04A Page 1737
I say this based on the fact that I found another birth registration with matching details for your grandfather, with the correct name and the correct year of birth (1927).
Due to RootsChat rules, you will have to remove your grandfather's name, as he is still living, but you are free to discuss deceased people, such as your great-uncle Arthur.
The only spanner in the works is that the death registration I found states that Arthur died in 1998, but this is not too far from 2002.
I can see that Arthur and your grandfather did indeed have 2 other brothers, but also 4 sisters.
Their parents were Edward Albert Barnard and Ethel Rose Kersey.
If you are looking for a free site to start your search, then I strongly recommend
familysearch.org.
Queenie