Missing key in art museum

[grimacedia]

I think I sequence broke the sticky notes - I found the fireplace key before opening the box that had the hint in it, and the key wouldn't work on any doors. I reloaded and the key is now missing from my inventory and isn't in its original location.
I wanted to check in here on if there's a workaround before starting the job over - I did everything else in the level first so it's hard to just restart.

[lotusflower444]

I also have this question!