I have recently been asked by a reader whether I plan to write a similar book about aircraft bubble sextants, such as the US A10 and A12 sextants of the Second World War. The answer is “perhaps when I have caught my breath after writing the Nautical Sextant.”
However, readers may be interested in my Mark IXA Sextant – A reconditioning manual, also available as an e-book. The Mark IX series of bubble sextants served the Royal Air Force right through WW II and beyond. Thousands of these instruments survive and in the view of many, including me, it was the best designed of all the bubble sextants ever made. I have recently revised the manual and added a supplement on the Mark IX. If you’re interested, contact me.
I have now (2020) written overhaul manuals on the A10, A12 and the SNO-T sextants. I also have official maintenance manuals on several others to refer to when people get stuck with an overhaul.
The Nautical Sextant 
Thanks, It is great to find sites offering great information to collectors
I recently bought an old RAF Mk IX bubble sextant. I also bought Bill’s repair manual and set to work on it. The instructions provided in the manual were clear and easy to follow. ( as with all his other books on old sexant rebuilds). If anyone desires a working RAF MK IX, I for one cannot recommend one more, I also highly recommend the same person buying Bill’s book on them. A must have for the enthusiast!