My GUESS would be that it is some kind of manufacturing sight index mark that was used during some manufacturing procedure during sight alignment...
But that is pure speculation from a manufacturing engineering standpoint... no documents to back it up.
__________________
regards, -John S
"...We hold these truths to be self-evident that ALL men are created EQUAL and are endowed by their Creator with certain UNALIENABLE rights, and among these are life, LIBERTY, and the pursuit of happiness..."
|