I am stuck on the old clock hand too, i've interacted multiple times with every clock that i can find (a broken clock after maze, a clock near fountain, two working clocks in a red room, a third clock from that room, that says that anne doesnt want to come back), but it doesnt do anyting, clocks in the mansion dont work too.
Also, in the description you mentioned, that there is the new ending, but red light in the gallery doesnt say anything about it