This is my first posting on Sawmill. My neighbor gave me a block plane which I have been restoring and cleaning, finding that I could possibly use it. The iron has "True Value" stamped on it and I'd rather keep it instead of replacing it. As I began flattening the iron, I discovered that the corners would take forever. Upon closer inspection, it seemed both of the long edges may be rolled a touch, as though it was designed that way--a cambered iron. I didn't think that would be done for a block plane, that it be for a smoothing plane. I have the Veritas Mk. II but without the camber attachment. Not seeing the need to spend money for that just yet. I would suppose my question is: was that really by design, and if so, is it really necessary to clean/sharpen those cambered corners? Any feedback to a forum rookie would be appreciated.