I would first request a photo of the stone at Find a Grave. You'll have to join (it's free). Of course there may be no one doing photos in Minnith Missouri, and sometimes it takes a long time for someone to get around to photoing. I see you've already done this, quite some time ago.
Another thing you can try is contacting the Saline Baptist Cemetery or the Saline Baptist Church. Assuming the death date is basically correct, you should be able to get a burial record, which may or may not list death and birth date.
Or contact the town clerk in Minnith and ask if they have death records. By 1906 most places do. If they don't have them they should be able to tell you where they are. The death record may have also a date of birth and parents listed, but in 1906 that is not a guarantee.