As an American it baffles me that an American editor would change the word disused but not the word lavatory.
One other thing. I’d rather have characters say ‘What do you mean?’ than ‘Whadd’ya mean?’
Again baffling. Whadd'ya mean is an accent, not a word choice. Changing it in text is as ridiculous as writing 50 as "fifdy" when it's an American character's dialogue.