NavList:

Thank you for this Bill.  I had the mirrors of one sextant done professionally many years ago but have another worth doing, so will try this.

As for the mercury, I do wish I had spent less time, as a youth, syphoning leaded petrol by mouth from a larger tank into the small tank for the tender's outboard motor.  And then there were those lovely lead toy soldiers handed down by my father which I used to suck on as a baby - I removed all the paint from them over time.  And of course on those cold mid-winter road trips my parents, both smoking, would thoughtfully close the car windows so that we children would not get cold. :-)

Ah, memories.  I think the damage is done.