Just re-checking what the Cyclopedia entry actually said.
http://nzetc.victoria.ac.nz/tm/scholarly/tei-Cyc01Cycl-t1-body-d4-d121-d3.html ... "Mr John GORDON the founder of the firm,
has resided in Otaki for over 40 years" ...
And it goes on to say ... he arrived in Auckland by the "Cashmere" in 1852 where he stayed for 2 years before coming to the district ...
[district being Otaki]We now know that the "Cashmere" voyage (through misfortune) didn't arrive in NZ until May
1853.By my reckoning, (and I'm lousy with maths), if this Cyclopedia reference was published in 1897,
> 1897 less say, 40 years = 1857
> less about 2 years spent in Auckland = 1855
> less another year ('cos he'd been in Otaki
over 40 years) = 1854
... overall, dates not too far removed from his "supposed" arrival in mid-1853.

~ Lu