Thank you for playing
I am glad you liked it so far.
I don’t know which version you played, but the latest version has some improvements to the hints/clues. However, they are not perfect yet.
As you already mentioned, the brown book does indeed have a clue about the clock. Also, the journal has a hint function, to the clock.
It seems you were close solving it. The books have to be set correctly in the shelf, before you set the clock, otherwise it won’t work.
I don’t know which chess pieces you got, but I can imagine you missed the one in the drawer. The others, you get from the girl and the zodiac box. The key isn’t important. It fits a trunk, but you don’t need its content to finish the game.