Is it "Harvey" or "Harmon"?

     For some reason, Grandpa Henry's name is in small dispute.  His COD (Cause of Death) Certificate has him listed as Henry Harmon Eller.  News to me, who always knew him as Henry Harvey.  It also played a little havoc in my genealogical search. 
For the Record, Harvey is correct; but this did cause a bit of confusion. 
     Aunt Ruby told me he always signed documents "H. H. Eller". Hmm.