Hedo Swedenbob,
I got one new, and got a few used tensioners. Do you want the spring and the mounting block as well? Don't forget to look outside the box. One of my C5's is fitted with this solution. It is from an old bike and, to be honest, is a better way to keep enough tension on your chain.
greetz
Frank. Ps. Are you coming to the meeting in the Netherlands in july? You would be the first Swedish participant! (there is a C5 parts marked as well)