On the original information I received from 'mackiwi' on Feb 2, there was posting she had found in Papers Past, Southland Times, 15th Dec 1885.
It says
'At Invercargill, on Monday, December 14th,1885, Roderick McLean, formerly of Rothesay, Bute, Scotland, aged 91 years.'
The age of this McLean doesn't match, but where he came from is where the McLean family is from.
I'm not sure if this lead should be ignored or not, but thought I'd send it anyway.