What a great score! They are really neat little critters. I see them occasionally being sold on liveaquaria.com. They are most often the pink ones with purple claws, though sometimes they have the ones with the little bandit mask.
They can be quite selective with they type of coral they'll live in. So, even if you do get another he may not move in to any of the colonies you have. I've seen them take to acros an pocillipora corals, but it can be a real crap shoot. They seem to do best when they come as hitchhikers. If the coral dies they usually do too, unless they can find another host coral nearby that's the right kind.