The "shelf" is browned for almost all of its distance.  Except the very front.  That's in the white.  As made that "shelf" on that rifle had a consistent finish on the entire shelf.  Imagine masking off a flat surface and finishing it.  Then removing the masking tape.  The bit under the tape wouldn't be finished.  Which is what we're seeing there.  The front of the shelf is in the white whereas most of it is browned.  When originally made it was all the same finish.  That is "browned" during rebuild with them missing the front of that shelf.

The receiver wasn't browned at SA.  It was browned during rebuild and they missed the front of the shelf.  The guide lip also has that inconsistent finish.  Ergo, the gun was arsenal refinished.

The reality is most were.  Far too many people assume the gun is "original" when that is in fact almost never so.

Very few guns are "original."  That doesn't move your rifle into the "junk pile" as most were refinished whether people realize it or not.  It's a nice rifle.  It was arsenal refinished as were most from that time.

They went to parkerizing on '03s for a reason.  They couldn't keep the browning from wearing off.  Quickly.  The guns were carried in the rain, sun, etc.  They lost their finish quickly.  When returned from the units they were refinished as a matter of procedure.  RIA's inventory reports only have two columns: new and refinished.  It was either one or the other.  SA, RIA, Benicia, and Manilla all had browning facilities and they all used them.  Heavily.