Probably not available as a seperate piece- if you have a drill (and maybe some taps) you or someone you know could make one? It looks to be a metal cube with 2 bolt holes thru it to take bolts one tapped (maybe M8) for the long adjuster bolt, the other just a plain hole for the lock bolt. If the whole thing isn't too dear, and is available, just but it before you wished you had, lol!