I have bought this set:
http://www.mediamixhobby.com.sg/cata...oducts_id=3541
It has new sprockets and the whole set. If you look at the original post, it contains a link on how to build the chain set. I would guess that if you removed the plastic chain and reused the plastic sprocket that it would be a pain and a waste of time. But, it could be done if you wanted to do so.