There are several good videos on how to remove Cosmoline if that’s what it is. The gun really looks nice and for 150$, I hope you feel guilty.
My one suggestion is to have the head space measured. That’s always a good thing to do with old military firearms.
The 03 is a gun that every collection must have. It’s as much of an icon as the Grand and the Mauser 98.
http://www.youtube.com/watch?v=lmElUyysyKU