G'day Mark, there is some light scoring on the cylinder but not much. The top ring on the piston was stuck at the point where it must have overheated. I gently moved both rings and now they are both moving freely although the top one feels like it has grit underneath it. Tried 2 mower places today for new rings, both said they didn't have any and would have to get them in. Is there any point in trying the current rings once the groove has been cleaned up?
Appreciate the info on rings, I didn't think there was that much to them but you've saved me some grief. Notice that you said that you honed your cylinders, is it worthwhile me doing the same on my cylinder?