I can't help with tritium hands, but these days if you have an issue with a "lower end" seiko automatic movement like the 7s26, it is about cheapest to replace it with a newer 4s movement. I have replaced a few, and the only thing you replace is the movement, stem, and crown. Pull the hands and dial, maybe swap the day or date wheels, depending on the movement, cut the stem to length, and reverse the process. You might install a new seal while you're at it. If you have it done, for a little more, they can regulate it.