Can I use the Automatic Taper Extension (ATX01TT) on the Mini-Taper (03TT)?

No, the ATX01TT Taper Extension will not attach to the 03TT Mini-Taper. The extension is designed for the 07TT. The ATX01TT Extension attaches to the control tube of the 07TT and requires the length/distance that the 07TT tube provides. The distance from the bottom of the taper to the control tube of the 03TT Taper is insufficient for the ATX01TT to attach.