Hi Forfarian,
'In the 1841 census, adults' ages were suposed to be rounded down to the nearest 5 years. So someone listed as aged 60 could have been anything from 60 to 64, and assuming that his ager is accurate he would therefore have been born between 8 June 1776 and 7 June 1781.'
'If accurate that would imply a birth between 31 March 1775 and 30 March 1776.
As these two sets of dates do not overlap, at least one of them is definitely wrong.'
'That, if accurate, would imply a birth in 1766 or 1767.'
So the period for a potential birth could span 15 years give or take a couple of years if you allow room for innacuracy.
'Be aware that Tyrie is a parish in Aberdeenshire as well as an alternative spelling for the Hebridean island of Tiree, next to the isle of Coll.'
I didn't know that there was a Tyrie parish in Aberdeenshire. Looking at the 1841 Tiree & Coll Census, under the column Where Born/if born in the County or state otherwise, next to John's name it says 'yes'. In the 1851 Cenus his birth place is written as 'Argyle Tyree & Coll'. And on the Chelsea Pensioner record for a John McKenzie, his birth place is written as Tyrie, Argyll.
'If he is the 75-year-old John McKenzie, Chelsea Pensioner, at Arinagour with wife Betsey, son John, daughter-in-law Annabella and daughter Catharine, the transcription I am looking at says that he was born in the parish of Canongate in the county of Midlothian. The census index at FamilySearch says he was born in Edinburgh. Canongate parish is in the city of Edinburgh. What does the original census say?'
On the 1851 Census, only Betsey is listed as being born in Canongate, Edinburgh. Everyone else is listed as born in Argyle, Tyrie & Coll. I too saw a second John McKenzie who was an Army Pensioner on the Isle of Coll, and found it quite a coincidence.
'Peggy is a pet name for Margaret. Does it say "Peggy McKenzie MS McKenzie" and if not, what exactly does it say?'
For John's parents - John MacKenzie (Crofter, Deceased) & Peggy McKenzie, Maiden Surname is given as a line only (Deceased). Although I have just noticed that McKenzie is spelled differently for John Sr. & Peggy.
Keelan