I can't really tell what the grain is doing further down, but from this end it looks like good bow wood to me. If you can watch an experienced bowyer chase a ring it will be a big help. Read the Traditional Bow Builder's Bible on ring chasing and then armed with that info proceed with your drawknife and scrapers. I have to get into a zen like ring chasing mood to even try to fool with it. If my mind and mood aren't right, I don't try to chase rings that day. It takes concentration. If you are distracted and in a hurry, you can sure mess one up quick. Those rings look good to me. Before you spend any time on that though, pick you a spot in the middle of that stave and draw yourself a line following the flow of the grain from one end to the other. If you have enough wood on either side of that line to make a bow, then layout your side profile lines always following the grain. If you need to straighten it up, you can do that later on down the road. Like was suggested earlier, once you chase your ring seal the back so it won't check on you. I like spray shellac for that. Keep us posted on how it goes.