NavList:

I notice that some units appear to have had the lever removed. It's hard to ascertain it's function. I've removed the worm gear. It appears that there are two possible positions for the lever and that my unit may have been wrongly assembled. Might account for its pristine condition. It's a bit of a puzzle. As far as I can see it may be intended to act as a lock or brake but would really need some spring pressure which I haven't managed to work out yet. Any pointers greatly appreciated.