I just cracked off a whole blade of a 15 x 28 RH flow torque Merc Cleaver. It has the old part number as opposed to the new part number. Can I just order 1 new prop with new part number or was this a matched set? Do I have to send the new and old one to be balanced and checked? These are on 300x's on 28 Eliminator. I am in Toronto so sending down to the states is kind of tough. Please let me know.