Will have to respectfully disagree about that: the "L0103" on the butt socket is original. The "88" is clearly a later over-stamping of the first two digits of the original SN; not even the correct sized stamps. The bolt is a complete renumber and another number was filed off first, so it is a re-used bolt, and looks like the hand of Bubba was upon it.
Why the SN on the socket was over-struck is anyone's guess: someone who liked "88", wanted to obscure the number of an "acquired" rifle, thought they knew what the SN "should be", etc. etc.![]()