Is there a rule of thumb on which batches of vintage Speedys still have a little glow left on their tritium dial and hands? I own a 145.012 that still has a faint glow in the dark at times on the dial and hands. And I previously owned a 1969 Speedy that also had a little glow left. I'm more into vintage Rolexes, and I have several early and mid-70s pieces that have absolutely no glow on the tritium, but I also know there were a batch of vintage Subs from the mid-'60s that still have some glow left in the tritium because the chemistry was different during that time period. I wondered if anyone knows whether it's the same with certain batches of vintage Speedys.