This is monter hunter freedom 1 there are no flat stone or nothing they just all say ???? and stuff.
From what the gamefaq ancient stone guide said was after you get a ruststone you save when you finish that mission then you go and polish the stone and see what it is and if its not a rusted weapon exit game without saving reload game but instead of polishing the stone right away do a quest and finish it and then polish the stone and they said it usually changes, this has worked with every weapon except the great sword ruststone no matter how many times i do missions.

Also thx for replying.