One thing to remember when looking at a rifle is to look at the whole. If everything on the rifle looks consistent in quality and condition, finish is original, etc. there is a good chance that the rifle and cartouche are original. Look at the forest as well as the tree.

A complete set of pics of this rifle would be nice. It appears to be an exceptional example. What we can see is a super nice original looking receiver, finish and serial number. To see such a nice stock and cartouche on a nice original condition original finish rifle would not be a huge surprise.