Given the age of the pistons they don't look all that bad. I have seen worse.

The pits are caused by low octane gas exploding from compression or unevenly when fired. They normally start to crumble around the edges but they can blow out pits like this as well.

I am rather stumped by the noise myself. If the push rods are OK then the only thing I can think of now is wear on the shaft the rockers ride on. This would mean removing the rocker assembly and removing them to check for wear.