Baptisms have never been a date of birth as so many assume in many trees I've seen. But from my experience baptisms occur even as an adult.
I have had many children baptised on the same day, no matter what their ages are.(A block booking, if you will).
In one instance a wife has been baptised long after her marriage, as
'wife of ??', and also my Gt Gt Aunty was baptised a week before her marriage at the age of 22.
I may suggest that you look for siblings of William Hawkins/Hawkings in Tring, then see if the ages match or not in the Census returns. Or at least in a time frame that is reasonably close to William's 'discrepancy' for his y.o.b and baptism..
The death cert or burial is a better indicator of the correct age, but even that could be rounded up or down a year or two, sometimes 3 years. It all depends who gives the information.
I would think that Williams wife Maria, as she survived him, or child gave the information to the registrar for his death so may possibly be more accurate.
Sometimes an age at death is different from burial age, again it's who gives the information.
If it's some poor old soul who's so old, that he's outlived most of his neighbours of his generation, then it's usually a best guess by those that knew them. Luckily for you William Hawkins had family surviving him.
Your William was living in Walton, Aylesbury, which is very close to the Canal. Baptisms give his occupation as a labourer, even though in census returns he was Boatman. That's no big deal in it's self.
Aylesbury Canal was a branch of the Grand Union Canal, which i believe passes Tring quite closely, hence, ending up in Aylesbury.
Steve.
