I don't have much I can help you with - but I see in the Bahamas Registration that Joel Moss and wife Leah Rogers Moss were living in St. Anne's Parish, New Providence by the 1940s. They had daughter Joan born 8 December 1948.
I also see a record for the marriage of an Elisha Moss, aged 23 years, of Lovely Bay, Acklins, and Carmelita Beneby of Lovely Bay, Acklins at Our Lady's Church, Nassau, 29 September 1936. The marriage record indicates that a Joel Moss was Elisha's father. Since this record indicates that Elisha was born about 1913, I suspect he might be a brother of your Joel Moss born 1919. Both to a Joel Moss?
Regards, Ann Morley Carmel