Try the Random Acts of Genealogical Kindness for finding someone to help you with Manistee County MIchigan searching,
go to this websitehttp://www.raogk.org/
Click on our volunteers, then on michigan, and scroll down to Manistee county.
There seem to be three that do public records and copying, perhaps you could get information on the wife who died in that county. Since the husband was alive when she died and he knew from whence she came in Norway, it might be in the records, like death certificate, or obituary. Or even the funeral home records, or church records.