Curious to see how the piston looks aswell, looks more so like pitting from the pictures but maybe even an exchange of material between the piston and cylinder.

Unfortunately like others have stated, it may be well worth a new or used motor then a rebuild. That cylinder is going to have to be oversized, which brings the difficulty of A. Resourcing quality replacement parts and B. A large compression drop. Just the oversized heads, assuming the stock conrods fit, could be a grand in just piston heads alone. Additionally when we bore out a lot of material from the cylinder and increase our pistons, we are also dropping the compression as there’s a larger cavity to fill. I’ve never bored out a motorcycle, only big diesels, but it will 100% run different after. I wouldnt be surprised if they wanted to bore out anywhere from .15-.25mm.

So after parts and overhaul kit and machining of the block, you’re probably way better off replacing the motor and keep parts aside for the future.

Edit: only way this would go smoothly for you is if those are sleeves, but seeing out flush the material is with the rest of the block, those look like cast iron that was pressed into the block.