Depends on what you mean by legal. The exempt quantity for tritium is 1 millicurie. So you can have that much without a license or having to follow any of the regulattions.

The mapreader would be legal provided the manufacturer acquired a license to manufacture these products. I don't see why they wouldn't be approved. The amount of tritium used isn't harmful to anyone even if they broke it apart and ate it. It is simply a paperwork problem, and of course it takes time and money, which many companies don't want to deal with. If you are bored and want some light reading (guaranteed to put you to sleep), you can read all about NRC licensing in 10 CFR Part 30.

Enjoy!

Greg