by being in the shadow of the much larger Westminster Abbey and across the road from
Big Ben and the Houses of Parliament.
The Parish records for
St. Margaret's are actually kept, and available for research, in Westminster Abbey.
One entry of interest
I found in St. Margaret's Parish Registers,
although not a Martin,
was the Baptism of Margaret Church, a foundling. Obviously
she was named after the Church itself so anybody researching this line is not going to go any further.