Might be worth looking at Electoral Registers on Ancestry?
There appears to be a May Roslanowski in London, 1959-1965?
And a Mary Roslanowski in London 1955 and 1956?
Also a Richard Roslanowski in London 1959, 1960.
Could "Richard" be an anglicised form of Ruszard?
Your local library may offer free access to Ancestry?