I had to read the thread after I was summand. First, 318 must be tough to get there?? that was a lot of work to get where you are..... Ok, you have taper, and by the looks of the cylinder, you might be .040 getting them to clean up.
318s are not really that hard to find its just I have this one here so why not. This one is already in my possession and I don't have any hot dates anytime soon so I don't mind putting the elbow grease in just to do it. If it's junk, I accept that but if I can make it run again then that's what I'm fixin to to do.
I stopped honing when I did because my stone hone ran out of stone before I finished, or at least before I got a far as I wanted to.