Hi
It must make for a very interesting family tree, with people from many different countries. Hard to keep track of, perhaps!
There is a James Martin born 3 Feb 1829 and baptized St George the Martyr, Southwark, 25 Feb 1829.
Parents John and Elizabeth, abode Kent Street, father a Labourer.
Well, I have now got hold of that merchant seaman's ticket. And I think it is looking likely that the James Martin baptized in Southwark in 1829 is your man. What do you think?
Register ticket 416,811
James Martin
Born at St. George's in the County of Surrey
2nd day of Feby 1830Capacity Ordinary Seaman
Age when ticketed 18
Height growing
Hair brown
Complexion light
Eyes grey
Marks Scar on rt leg
Can write Yes
First went to Sea (Blank)
(Has served in the Royal Navy - also Blank, so presumably no)
When unemployed resides at 30 High(t?) St
Issued at Shoreham 26 day of June 1848
All of the tickets on that page were issued at Shoreham.
So his date of birth is the same as you have, 2 Feb. On the baptism in Southwark it was 3 Feb (very close!)
I think James may have lost a year from his age on this record, and a couple more when he joined the Royal Navy. He would have been in his mid twenties in 1854 and probably decided to say he was a bit younger.
There seems to be a trail here from the marriage of John and Elizabeth to the baptism of James to the sea record(s).