What To Do With An Unwanted Rainbowfish?

Having bought a second hand tank which included a few fish, one of them is a lonely fully adult Lake Kutubu rainbowfish. He/she is in with inappropriate tank mates, i.e. seven little tetras, and keeps them confined to one end of the tank. I could move it into a bigger tank, but it needs to be with more of the same species and getting more doesn't really fit in with my plans at present. In any case, the fish on sale are always so much younger and it would probably be a year or so before they would be a similar size. I'd like it to go to someone who has the same species already, perhaps breeding them. I don't want any money, just for it to go to an appropriate home. So what is the best thing to do? Is http://www.aquarist-classifieds.co.uk a good place to try? Obviously it would need to be picked up from here (Midlands). Any other suggestions? It's such a beautiful fish and deserves better.