Inconsistencies

[Pitchwife]

Originally Posted by Galin

It didn't necessarily say Moria on the actual door however.

It does on Tolkien's drawing of the door in LotR: Ennyn Durin Aran Moria. Following the translator conceit, this would be a copy of a drawing in the original Red Book, done by somebody who had seen the door (Frodo or Sam, presumably). That's as close to the actual door as it gets.
It probably should have been Ennyn Durin Aran Hadhodrond, with the Sindarin translation of Khazad-dûm which the Elves used before it was renamed Moria (see Silmarillion index); but apparently Tolkien hadn't invented that name at the time of writing LotR.