Single lever washing machine shutoff

I've got a single lever (Watts?) shutoff on my washing machine supply. It's brass and the lever swings horizontally from right to left to perform the shutoff/on function. The lever started to move very easily and now does not shut off the water. My guess is that this can be rebuilt/repaired. I haven't look at what might be wrong and was hoping to find a repair kit and some help on what may be wrong before I tear it apart. What compounds this is that my main shutoff no longer really shuts things off. I'm in the middle of a row of townhouses, and the main shutoff is not accessable easily, and would turn water off for 10 homes. I guess that the washer is probably shot after 20-years! How do you usually handle this sort of situation?

Items like this are not made to be repaired. Unless the valve has some standard components like off-the-shelf o-ring sizes, the chance of finding parts is very slim. If it is Watts, you could contact them through a plumbiing supplier, but I would be planning to replace the entire valve.