The old "knurling the pistons" trick, right, Chief? It actually works. But try to find someone who knows how to do it!
About rings, the bore wear is probably greatest close to the top. If you use file-fit rings and set them to the correct gap at the top of the cylinder the odds are they'll be really close or butting at the bottom of the stroke.
I know my first reaction was "yuk" but I've run worse than this.
