The information you have is taken from the GRO index of marriages - in which names are shown as Surname + First Name + middle initials. No other titles or qualifications are shown so Da S must be an abbreviated name.
There is a passenger list in 1951 showing Annie M C Da Silva Dunford taking a trip from the UK to Lisbon with husband Charles and daughter Veronica. Charles is a vicar and the address is "The Vicarage, Gt Missenden, Buckinghamshire".
Gt Missenden is only a few miles from me.