Pete, Richard Notter, who died in 1852 and who I believe was John's brother left in his will £5 per annum to “his nephew John Notter during his minority”. This I would imagine was the man in the photograph. I would be most interested in seeing the photograph - perhaps you could scan it? My email address is email@example.com.
I have also written quite a few pages on the Notter's of Rock Island which you may be interested in. If so, please email me. Aidan