The Delta County Genealogical Society website states that Sac Bay Cemetery is owned & operated by the township, and is still active--http://dcmigs.org/cemetery/fairbanks_twp/sacbay.htm
You could try calling the Fairbanks Township supervisor at 906.644.2022 to see what records they might have.
As for funeral homes, I haven't yet had to resort to funeral home records, so I don't know what might be available. But yes, the body would have normally been shipped to an undertaker or funeral home. You could try contacting Anderson Funeral Home in Escanaba at 906.786.4232. Their website states that they've been in business since 1919 and it's still owned by members of the same family. Skradski Funeral Home in Gladstone has been around a long time, too, but I don't know just how long.
Have you also tried looking for a church record for the burial?