Back in 1961,I had a 38 coupe that suddenly ran on 7 cyls.when I pulled the head,the piston looked like yours.The top 2 rings had broken into small pieces & destroyed the ring lands & worked their way to top of piston.There was a slight hole worn in side of cyl as well.I patched it up by getting a new piston & rings for one cyl.It ran on all cyls again & I was able to drive the 1,000 miles to get home with a smooth running engine.A month later I was able to buy a 10,000 mile Ford rebuilt engine for $50 and it went in the car.I would think that if one piston is bad,the others wont be all that great either.Likely the engine will need a rebuild.