I was visting family in northern Indiana today. Since I was near to Culver, I went by the Poplar Grove (aka Maxinkuckee I.O.O.F) Cemetery to check on Orean's burial location. I turns out that he already has a brass military marker on his gravestone. In fact it is mounted on the top of a red granite base and serves as his gravestone.
Based on the condition of the brass marker, it appears that has probably been there since Orean's death in 1974. Therefore, the one that was recently found in Texas was apparently a duplicate. Perhaps, it was defective in some way and another one was produced back in 1974.