I have a Superscope TDR 820, i am looking for a belt but cant find one, the size is 12.1 inches OD 1/4inch (6mm) wide 1mm thick, the thickness isnt that important, and the width doenst have to be exact, but should be close, ive found belts that were 5mm thick and less, but this unit has a rounded pulley and they dont work too well, anyone know where i can find one?