Despite the lack of interest in my thread, I did resolve the problem. I did remove the piston and measured my wall clearance at .002. Ordered new standard size rings from ebay, checked end gap which was within spec for both, gave the cylinder a light hone and reassembled. Also adjusted the air screw on carb after 20th cleaning. Bike starts and runs good now.
Now that it is going good, I found I have leaking seals on the oil pump that I will need to replace. Fortunately they are still available and cheap.