Amer, have a read through all of this thread and maybe do a search for tritium for some more background on this.
Regulatory, import and other authorities around the world had been making noises about the use of tritium in the 60s, and certainly by the timescale of a 2nd execution Dato 45 Heuer, and many others, were experimenting with photoluminescent materials to replace traditional self-luminescent radioactive ones. We see many manufacturers phasing out tritium at the end of the decade and most general use watches were using a substitute lume by the mid-70s. Heuer seem to have been quicker off the mark than most, the Chronomatic watches already used non-radioactive materials. Tritium use is still permitted, though under much tighter regulation - watches using it now tend to have it contained in tubes.
Military use carried on longer than on watches for the general public - reference the 3H Bundeswehr watches.