How about
: Gandalf said Moria and the translator followed this for readers, with his inscription in the modern book. So the real inscription might read Hadhodrond instead of Moria (despite both being Elvish), just as the real inscription did not have Durin and Narvi.
The picture of the door in the modern book is still effective enough, giving an idea of what it might have looked like in general, including a general representation of some internal language and script. The runes in
The Hobbit are Anglo-Saxon based, but since the actual runes as used by the Elves and Dwarves are 'similar enough' in design (at least), they lend an effective element visually, to the story.
Of course Tolkien may have just made a mistake with Moria, but if one is looking for an answer beyond that, for myself, since the Dwarf-names appear
in the written example in the book, and must be translations,
Moria can also be a 'stand in' -- even for another Elvish word -- given that Moria is the name the Reader knows.
Or something
Edit: I didn't see Pitchwife's recent response when I posted this, by the way.