Japan National Railways, Model: ED171040 is remodel to ED50, then remodel to ED17 Type1.
Original 6000 is remodel to ED52, then remodel to ED18 Type1, finally remodel to ED17 Type2.
New 6000 is remodel to ED51, then remodel to ED17 Type3. 1030 is remodel to ED13, then remodel to ED17 Type4. Type1: ED171 to ED1717 Type2: ED1719 to ED1723 Type3: ED1724 to ED1726 Type4: ED1727 to ED1728