what are these?

Well, despite some peoples advice I decided to reinstall new valve seals and not go through the motor. At first I tried to replace the valves with the heads on the motor. I rented a valve spring compressor and an adapter to fill the cylinder with air. The air cylinder adapter leaked real bad and I couldn’t keep enough air in the cylinder to keep the valve up when I tried to compress the sping. I decided to just pull the heads. I’ve been wanting to upgrade to a four barrel carb and I picked up a Performer intake manifold at Pick and Pull a couple of weeks back.
I pulled the drivers side head first and everything looked good (well at least to me, I really don’t know much about cars). When I pulled the passenger side I realized that I’m screwed. The number 4 cylinder is missing a portion of the piston.
I haven’t had the car very long. It did smoke, but not on the side where the bad piston is. I had done a compression check and that cylinder was lower than the rest. Most were in the 145 range and #4 was around 120-125.
Well anyways now I got to figure out what to do next.