Your acceptance 'cartouche' letters are J.S.A., which stands for Joseph Sumner Adams, Assistant-Foreman assembly room at Springfield Armory.

As you stated, your Krag's receiver, #175829, was manufactured in 1899, (likely, around January or February).

The explanation for the presence of a stock, dated 1901, with a receiver from 1899, is that most U.S. Krags were rebuilt during their use by the military.

When Springfield Armory, U.S. Arsenals and Depots were rebuilding Krags, the rifles and carbines were taken apart.
The serviceable parts were refinished and went into bins. Rebuilt Krags were assembled from a new combination of randomly selected parts.

In brief, your stock is not the first one that was on your receiver. The stock was being reused. There was no reason to "redo" the acceptance cartouche, the arm had already been accepted. Old stock markings were not purposely removed.