The blade's sheath is just as awesome as the blade, agreed...
But I'd like to contest your interpretation, for I don't think that's Common Tongue.
As with so many other pieces, I'd say that the inscription of the scabbard is Sindarin.
Im Andúril dcnnn ne Imladris () Narsil ristnnn
Here's a compilation of the sheath I did after RoR's release...