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Mr Link is most insistent that you should remove the batteries from your A12 when not in use to avoid contamination by leakage from so-called leakproof batteries.  If you do so, even a near perfect A12 can still give you problems. If the empty battery containers are pushed in too far, it’s the devil’s own job to get them out again, because there’s nothing to get hold of.  This happened to me recently.  Encouraged by Geoffrey Kolbe, I presented my A12 with a new bubble and took it on holiday with me.  Pure acetone nail-varnish remover plus scraping with a needle to remove the sealing varnish freed off the tiny ball-bearing beautifully. The empty containers had got pushed in too far and refused to come out.  I managed to get a wrench on the index arm illumination container and gently work it free, but the bubble illumination container couldn’t be removed without risking damaging the rheostat.  In the end, I had to ping the round wire circlip and the window from the daylight hole and push down on the bubble illumination bulb. 

So how could I prevent this happening in future?  Suddenly epiphany! Why not make some ‘sleeper cells’ out of a suitable broom handle?  That’s exactly what I did.  You need to experiment with longer and longer dummies until you get just the correct length of container sticking out to get maximum grip without making it impossible to get the sextant back into its case or prevent the bubble illumination head being gripped by its case.

Now I only have two problems.  Remembering where I carefully hid the round wire circlip and window so I wouldn’t lose them and avoiding going head over heels on the test sleepers I discarded as not quite long enough.  DaveP

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