Think I Missed Something (Raven)

Hi. OK so I was up to this part in or near the secret room - I applied the raven to that hanging bag & it appeared to be the proper thing to do but then it looked like something had fallen down to the floor .... or maybe something occurred by my doing that.... but whatever it was, it happened so quickly that I missed it & I cannot figure it out.

At the same time, just a moment before or after that I had a similar issue! There's a door in ohhhh I want to say it was in the courthouse but again I am not sure I recall. I think I applied some parts to it but before gaining all of the needed parts.
So I went somewhere & obtained a chain - but I cant seem to get that to go onto the door. I really think its supposed to! Could be wrong.

Advice? TYVM in advance.

The raven knocks something down and it falls by the armor. Look down there. I remember almost missing it too.

I played more than a week ago but I seem to recall that there will be SEVERAL items you need to open that door. I remember getting the chain but having to wait for several other parts before the chain will work.

Hope this helps.

There was a button or knob that went on that door to hook the second chain around. I can't remember where I got the knob.