The Pontiac Press was also active in 1920. It's now the Oakland Press. Other names it's had are the Pontiac Daily Press, Pontiac Gazette, and Oakland Gazette.
I would check with the Oakland County Pioneer and Historical Society - www.ocphs.org
, and the Pontiac Public Library - http://www.pontiac.lib.mi.us
, to see if they have obits for the paper.
You can also check seekingmichigan.org for death records through 1920.