I had been playing around with old compasses and aircraft instruments for some time before I actually sat down and thought about Radio Activity and Radium paint. Slowly it dawned on me that "Dead Radium Paint" may not be without Radio Activity. The Radio Activity was quoted as having half lives of thousands of years yet the paint was less than a hundred years old. I decided the best way to find out was to get hold of a Geiger Counter.
Anchor Surplus were active at the time in Nottingham and I soon found myself a few Civil Defence Detectors. Although uncalibrated they showed there was activity from "Dead" paint. Gulp! Fortunately I had usually cleaned off dead paint by scraping with liquids like white spirit or alcohol. This would have kept the dust down. In any case the quantities were very low. I seem to have got away with it. So far at least.
BE ADVISED Take great care not to disturb Radio Active Paint.
Now, many of the American sextants use huge amounts of Radium to illuminate the bubbles. These instruments are going to be "Hot" by anyone's standards, though bear in mind their danger was not known or appreciated by the users in the 1940s.