Heyllo...
Bad News: I have a Tomy Sprocket, but and defiantely not willing to part with him.
Good News: I know where you might be able to get one. Check out the following site...
http://home.snafu.de/cyber.bernd/fraggles/indexe.html
I purchased my Hasbro Boober from him and couldn't be happier with it. He's located in Germany, but shipping wasn't too bad to the states. As of now, his site says that he does have at least one in stock, though I'm not sure how often he updates, so just write him and ask about it.
I've had four Sprockets in and out of my hands over the years, acting as a middle man for other collector's after I got my own, so I'll also keep my eyes open elsewhere in case I happen upon one and will be sure to let you know if I do.