the one thing to check after index is fixed. is the front sight...iv seen some were the sight was bent in a attempt to fix the sight picture...some so bad it ruined the sight base.
just fixed a 1903A3 that had this issue..after i repaired his index. i had to replace the front sight..
the gunsmith he had work on it, couldnt get the barrel loose, so he just tried to bend the front sight over to get the sight picture right...