UPDATE:
With the generous assistance of a Find A Grave volunteer, I was able to locate Macklyn's gravesite; she was able to go out to the cemetery and obtain this photograph for me.
Still working on the details of Charles Macklyn Brown, but I did locate him in the 1940 Census Edwards, St. Lawrence County, and I also found a book that contains an extensive genealogy for the Brown Family in which Maclyn is listed. So work is progressing on that front slowly.
To view his Find A Grave memorial click on this link Charles Maclyn Brown.