NavList:

Martin,

there are some quite common metal work weaknesses which cannot be easily picked out in an on line auction listing:

        seized mirror adjusters

       ( for a sextant with an illuminated scale ) there can be corrosion problems around the battery box

        aluminium alloy sextants can have problems anywhere with salt water corrosion -  not all aluminium alloys are equal in quality.

IMHO recent Freibergers have very brilliant optics. I have a 2010 model. These sextants are, however, tricky to dis-assemble and re-assemble for servicing. The guy who won the recent round the world single handed 'no electronics' yacht race had two Freibergers, and hit trouble with both of them because of salt water ingress into hard to service parts. But if you are not going round the world, that may not matter to you. 

My favourite telescope of all is the 4x40 German bronze model standard sold on C&P sextants in the 1980s. Someone else may know the full range range of its manufacturing dates.

It is very re-assuring to handle and inspect any instrument before you buy it. It is well worth waiting for such an opportunity, particularly as there seems to be a steady supply of second hand sextants in Germany. eBay does give a good indication of prices; you can use the 'advanced' search to find the prices of previous sold listings for any particular model.

Having learned to use a plastic sextant, you may be surprised by the weight of a bronze sextant. Again, handle before buying....

Because we yachtsmen generally have only two hands and take sights perhaps without assistance, the sextant box matters. Life is easier if the navigator can leave the box open on the cockpit seating and then, after a shot, temporarily stow the sextant safely in the box when it is set at any reasonable angle. And rubber feet on the bottom of the box (easy to fit after purchase) help keep things in place in a seaway.

All the best with your purchase

Michael Bradley