I think I have information regarding the Guyanese Nunes family. My grandfather is Kenneth Francis Nunes, I believe he was named after his father, and he lived in both Guyana and Aruba where he had many children in both places, before finally settling in Guyana. The Nunes family eventually moved to London England in the 1960's.
If you think this has any relevance to your questions I can look into it. Unfortunately my Grandad passed away in 2005 but I can ask my other family questions regarding his life in Guyana, his parents and his grandparents.