Jim it looks like in the photo you may have too much oil on them when you season. Be sure and wipe them down and then wipe then again. It will keep it from making the little splotches. Like Gary, I avoid the flax seed oil. Many reports of it flaking off over time. You got some great cast iron there. You mention the steel wool, I would get some easy off. The one with lye in it and spray them down and put in a trash bag in the sun. A lye bath or electolysis set up would be even better if you plan to do a lot of pieces. It is much easier than trying to use elbow grease to get the carbon off.