Re the birth registrations ~
Also consider an illegitimate birth - so ask for father either Samuel or none
I say this because my grandfather gave his own name on his marriage cert and he was illegitimate and did not know who his father was so, for propriety, he gave his own name. It was fairly common to do this in such cases.
In your case you have - for definite - him as a boarder in 1911 and the marriage cert and a date of birth from his death cert

Sorry to add another complication but thought it was worth mentioning, just in case.
Also, have you thought of looking for his obituary in the local papers. I found lots of relatives that way.
gnu