That's a good point.  Even an 1892 may have a 1902 sight on it.  It would be hard to narrow down, although an 1896 Krag with a 1901 sight and a stock with no cartouche issued to a National Guardsman stationed in England in 1917 would still be "As Issued" because it was issued by an armory to a serving member to be used in service!

It does murky the waters just a tad...