re Manx certs see
www.manxnotebook.com/famhist/genealgy/refs.htm
Re road I have record of a South Rd/St in Rushen (there is a south view etc - there is no South Rd/St anywhere on the Island from my now somewhat old A-Z) - Bradda South is however a residential district in Port Erin (you might be able to check as manx telephone directory has a street directory)