i am thinking that its starting to come together - however absolute proof is elusive.

The Birth Cert is correct in that the Father is given as Engine Driver and mother Isabel - however I'm not convinced that Isabel is his Mother. I feel that the scenario is that Bertha Williams may be the mother of Harry, she probably is living in London with parents William and Elizabeth - but is sent to her Uncle / Aunt in Norwich ( carrying Harry) who register the birth as theirs rather than Bertha.

Her Father William has the connection to Walford, and I suspect Ann Morgan ( becomes Parker ) his adoptive Mother.

with Bertha as Mother - this gives a clear reason for London being his recorded "birthplace" in his "story"

As I say this is feeling rather than Proof.

First name(s) Berthalina Maria
Country England
Last name Williams
Volume 4B
Birth quarter 2
Page 5
Birth year 1877
Record set England & Wales Births 1837-2006
Mother's maiden name -
Category Birth, Marriage, Death & Parish Records
District Yarmouth
Subcategory Civil Births
County Norfolk
Collections from Great Britain, England