I also discovered that you can get an extra 20mm past the marked scale. .... Has anyone dismantled the actual scale bit to look inside? Similarly, has anyone found a source of the scale elements on their own?
The scale is (I think) just a PCB in (another guess) a sinusoidal shape. A source of the scale 'tape' would be VERY useful; It could be just stuck to the side of a mill table, for instance, and be read by a close fitting head (no bulky scale of PITA fixings).