Yes, hello. Sorry I didn't recognise the screen name when I posted. My mistake of the birth year 1876 (over tired :-) ) My David's birth date is definitely 13 May 1875 as I have the certificate. I hadn't seen the tree with the 6 September date. I'll go look at it later.
I forgot to email you the marriage and death certificates for the David I was chasing up in England. I'll email you all the research that I and some helpers did into him.
The David Porter born 1876 is not the David I was chasing in England. GRONI has U/1876/11/1002/10/470 David Porter 1st July 1876 Male Calaghan Armagh(pre-1973 Q4) As you can see, his mother's maiden name was Calaghan. I can't see a baptism for this child on familysearch but GRONI also has a sister for this David by the name of Mary born 1878. Her baptism (Mary Jane) is on family search showing parents to be Thomas Porter and Lena Calaghan.
My missing David and the one in England both have a mother called Ann or Annie so neither of them are this David 1 July 1876 as shown above.