It's not likely this was the same John Coffey, as the ET bio for John Coffey the stoker lists his death as occurring on 12th June 1957 (his bio can be found at
https://www.encyclopedia-titanica.org/detail.php/1439.htmlon).
And the address listed on the articles is 12 Sherbourne Terrace, Queenstown (the relevant page with Coffey's sign-on info can be found at
https://www.encyclopedia-titanica.org/pog/crew_pog_engine_book_03.shtml).
Hope this is helpful.
A few years ago I had the privilege of being able to visit the Cork Central Library and peruse the Kelly's dtreet Directory for 1912.
I found that there were 9 addresses where the occupant was named 'Coffey' and 3 of these were Mrs Coffey. If we remember the strict religious attitudes it is easy to assume that were the address is Mrs Coffey it means that the woman is separated by agreement, work or prison; since divorce was unthinkable at that time.
We know that John Coffey was married and originated from Cork and thus, had a wife and mother in the town.
It was not at all unusual for a seaman to sign on to 'Work his Passage' thus signing on in Southampton and signing off in Queenstown.
For ships the size of Californian or
Carpathia the Crew signing Officer would have filled in the forms and crew members would have retained their Service Books but for a ship the size of Titanic the Signing Officer would have collected the Service Books so that he could fill them in at his leisure.
In this case, if John Coffey had 'jumped ship' his service book would have still be on Titanic thus, when, on the Sunday he signed on aboard the Mauretania he would have no Service Book and thus, would not have been accepted.
Thus, if John Coffey signed on as far as Queenstown (not an unusual event for Irish crew members) when the ship arrives at Queenstown he reports off watch and goes to the Signing Officer and receives his Service Book and three days pay then gows and visits Mummy and his wife.
