Removing rust scaling on cylinder?

This bike I just pickedup had been sitting for nearly 8 years. Thus, water had found it's way into the cylinder and there is rust scale built up on two of the cylinders. is there a way to remove it without having bore or reline the cylinders?

Here is how the pistons were when I pulled the head. Here I have sprayed them with penetrating oil, letting them soak.

Is it just surface rust?Maybe try some carb cleaner and a green scuff pad.

Problem is that as you scrub them, the debris will fall down and get trapped in the rings.

I've aleady got the cylinders off the pistons. There was rust and water stuck in the oil rings. So I will replace all the rings to be safe.

Something few people know. When the cylinders rust, they are stained far into the metal. Back in 87 when I was rebuilding my bike after the wreak, I had a set of Z2 750 barrels. The 903 ones were bored off center by this guy they called "nigger Lee." I don't know why everyone called him that, ( he was Jewish), maybe I do. Any way, I had Clupper racing bore out the 750 barrels to 1015. Lots of meat to take out, they were mad but did a fine job. After all that metal was taken out, I could still see the rust stains. Didn't hurt anything and I still have them stashed away. I bought some KZ 1000 barrels on eBay and that's what I'm using now. (barley fit). The 903 barrels would overheat if bored more than 1015, not much room anyway, but now I can go out a lot more if I want to.
Just saying.
Steve