That BC tells you quite a lot.
The fact that both parents signed as informants means that they went to register the birth together, but acknowledged that they were not married to each other.
The way the mother's name is shown would certainly mean that she said she was (or had been) married to a WILLIAMS. But more rarely it could also indicate that she just said she had changed her name from Williams to Ambrose at some point in her life.
It would be quite normal for hotel staff to "live in" so you can be fairly confident George Broomfield was working as a cook at the London Hotel, and living there.
The Perey Clifford ( probably Percy ?) is just the name of the Superintendent Registrar who added the word "adopted" to the entry when he was notified by the court - nothing to do with any person or company who dealt with the adoption.
Following from this thread, I have begun to look into Sybil Ambrose, the mother of my Grandfather (Robert George Dixon). Today I received a copy of Ninette Williams' Birth Certificate(Born 1923), Who we have discovered is my Grandfathers Half Sister (We also discovered he has a Half brother- Leo J Williams- Born 1921).
The Birth Certificate has revealed that Ninette's Father was John Edward Williams (My Grandfather's Father was George Broomfield), The birth certificate also gave us the following:
"Name, Surname and maiden surname of mother: Sybil Barbara Williams, Late Conrad formerly Ambrose."
Ambrose is clearly the maiden surname that Sybil went by, At the time of Ninette's Birth (1923) she was married to the father, John Edward Williams. I have found a marriage between Sybil B Conrad and John Edward Williams in 1920 at Christchurch, which seems correct.
I am assuming the "Late Conrad" suggests she was married before Williams, and widowed, but I cannot seem to find any marriages between Sybil Ambrose and Conrad, It doesn't help that Sybils Surname seems to change regularly and I still cannot find her birth records. I am thinking she was born approximately 1899 and I have ordered what I believe to be her Death Certificate (Bournemouth 1933) So hopefully, that will provide some information.
In the mean time, I thought I should post here to see if anyone has any suggestions of where I can look/ if perhaps the "Late Conrad" could have some other meaning.
Thanks.