Really, I thought you get the 3rd and 4th (upper gong pieces) in the same way. (by moving the totem into the centre of the mosaic)

I am trying to get the upper left piece of the gong. My villager was carrying it when he dropped it due to the villagers celebrating the upper right piece being put into the encasement. Since then I have been putting the totem into the center of the mosaic to get the upper left piece again, but it wouldn't reappear.