Have you sent for his obituary from where he died? It soemtimes tell you who and where his parents are from or show siblings.
I have a John Davis that I'm stuck on. John S. Davis
Born: March 1st, 1857 possibly Illinois as a 1900 census which shows him states both his parents being from Illinois.
Died: July 13, 1923, place unknown
Married: Ellen Elizabeth Murphy Born: August 25th, 1866, LaHarpe, Illinois Died: July 24th, 1930, Keokuk, Iowa, Lee Co.
I noticed you had a Leon on one of your childrens listed. John and Ellen had adaughter named Leona and from what I could tell I think all there children were named after someone. They also had a Dale Orrie. Look for the Davis's in Illinois here by Teri and it shows his family (wife childen). They were known to be in Keokuk,Iowa, so maybe your Orion and my John could be siblings?