Are the part numbers for the body, base, etc, the same for service replacement and original q-jets? I have what appears to be a SR 7028264 (julian date 2660) carb, but the part number stamped on the body is 7034973 and the part number on the base is 7037174. These are different numbers than what my notes say should be on an original 7028264. Either my notes are wrong, the carb's been re-stamped (why someone would create a re-stamped carb is beyond me), or parts were interchanged on SR carbs...or is there another explanation?