One of the most useful sources of information is the official record of Births, Marriages& Deaths which I listed when the records were held in London on open shelves.
From approx 1911, the child's mother's maiden/marriage name is given in the Birth Registers.
From approx 1969, a person's DOB is given in the Death Registers:
These are the entries that I found:
I have summarised the entries in the name of Brecht, in a BMD Name Index
I have also listed details of the BMD certificates that I obtained:Colin Bower
4 April 2021
Links to:
BrechtBMDNamesIndex.html