Glad you enjoyed the post! Interestingly, despite the low efficiency the calculator amorphous panel was by far the most efficient choice for tritium cells that I tried, even beating out the similarly-sized garden light panel, which in sunlight would be more efficient. The calculators are built to charge in low-light (indoors) environment, so they end up working quite well for this application.
It's a shame that link doesn't give out the activity of the tritium content, but I suppose they don't want people to know that it's radioactive (the word tritium isn't even mentioned on the page, even though that's definitely what they are using!). Either way, I'm sure it would produce a much better cell.
Well, all their products are based on Tritium ilumination, and they do talk about radioactivity, proper disposal of their products and so on. Being a dutch company, and working for customers like armed forces and NASA, I'm sure they comply to EU regulations on radiation limits and radioactive substances. But no, they dont state the radiation output of the torch, but they say the light output is 1,000 µL. They also dont say anything about the price, but I think it was something like 50 or 60 Euros when I saw it on Amazon (its not there anymore).