Amateur watchmaker here. Its half life is ~1600 years, so it's still plenty hot. Hot enough, in fact, to burn out the phosphor in the radium paint, so it stops glowing, but flakes off as radium dust as the binders in the paint break down. Radium produces mostly alpha radiation, which is blocked by glass or your skin, but if you inhale or ingest the particles, it's not good for you, as the alpha particles will go directly into the surrounding tissue. The people exposed to the worst of it would be the ones stripping the radium paint off the dials and refinishing them, as that generates a lot of dust that you might inhale.