There was the hint about all the oil being dimmer near the rear entrance, don't leave the keys downstairs ( assumed this was about the room prior) and something about cost of ladders and 607 and some other number being important. I don't see any numbers, there are no ladders, and when I find a dimmer room I can't find anything to click on and if I try it gets me to the next room.
I skipped it and realized how you did it and an arrow appears in a room where it wasn't before. I don't see how that is a clue. I mean i guess the crossed arrows maybe? But that's a huge stretch