No idea myself, haven't had a close look but BS may be able to shed some light on it.
Hmm, good question and not one I can answer I'm afraid. I've never seen one actually used in anger but have seen one garaged at an Exchange on a different patch to mine.
I have unfortunately witnessed a lot of Cabs demolished by vehicles ........... myself and a colleague chatted about this a while back about how the older you get, the more you tend to feel
exposed when working at the side of, or on carriageways.
Speeding drivers really make my p1ss boil !!!