Parts fell out while fixing - need to identify

I recently spilled a small amount of water on my closed MacBook, which seems to have gotten into some of the ports on the left side towards the back. After that it wouldn't start.

The Apple store told me I needed a new logic board and a new display, which would cost about $850 or so to fix - almost the price of a new Mac. Having nothing to lose, I took it apart to see if cleaning it might restore its function (unlikely I know).

Unfortunately two parts fell out of it during this process and I don't know where they go. A small thin black flexible strip about the length of a toothpick and 1/2" or 1 cm wide fell out of somewhere, I believe from the logic board. It has a bar code and "W891506B76KNA M97A 2.4 BEST" printed on it. The other side is shiny black, slightly sticky, has the letter "A" on it and looks like a tiny piano under the magnifying glass. It fits perfectly on top of that long rectangular part of the logic board with the two little white stickers that lies underneath the speaker assembly, by the way.

The other part that fell out is a little 1 cm long spongy cylinder like a cigar or a short piece of a plant stem with tubules inside. There are longer pieces of this stuff along the hinge side of the machine. Maybe they're just cushions.

Does anyone know what these parts are and where they go?

Thanks.