You are going to need new pistons. Cylinders can be bored oversize. What do the bearing surfaces for the con rods on the crank look like?
Water jackets looks horrible, what kind of water was it run in, salt?
It will cost more than $100 to fix your engine, even if you just hone and replace the rings. It would run for a while. How long? Who knows. Of course if and when it does fail, it will be at least 8 miles from shore, just before dusk, and with a huge storm heading your way
Myself, I would hone it, remove any high spots on the pistons, re ring, and reseal it, and then run it. Never going further than a reasonable rowing distance from home. But I would just want see how long it would last.
For $100 you can buy another potential set of problems, but it might be a good buy