Hi Lois, It is more difficult to find someone after the 1930 census because that is the most recent Census available to the public at this time.
I think you need a volunteer who can look up his name in the Portland City Directory around 1952. If an Ivan Osborn is found in the Directory there's no guarantee that he's your Ivan. There is a volunteer at Random Acts of Genealogical Kindness. Go to www.raogk.org, read guidelines, choose Oregon, choose Multnomah Co and choose one volunteer.
Do you know who his parents were and when and where they were born? Then I'll look for them and Ivan in the Censuses. Happy Holidays!