Looks like you found the issue! I think you’ll find that your piston skirts will look even worse. You may even have tight rings due to close up ring lands.
I think we can confidently say that my advice to give it a good thrashing was highly unlikely to have helped!
If oversized pistons are available, why on earth are we discussing new liners or nickel plating the bores? Just buy some new OS pistons, rebore, enjoy!
I agree with the above poster ref ensuring the engineer listens to your instructions, those more familiar with modern engines really do struggle to believe / accept our requirements!
You threw us a bit of a red herring here click. As you have only just re fitted the head, we had assumed that the bore must be in good condition, otherwise you’d have seen it and fixed it.
There is a lesson for you here to check more carefully in future. Whenever you intervene in an engine like this you should ALWAYS check EVERYTHING.
You removed the head to fix the head... rather than remove the head to investigate the problem.
In fact, when intervening in an old engine, we should see it as an opportunity to look for early signs of any / every problem we can find, in order to fix it before it happens.
Not preachin’ ... jus’ sayin’ ...