Did you get a Towbar?
I'm in Melbourne and took one off my 2nd Hand 2004 ST1300 about two years ago.
Couldn't bear to get rid of it (You know "Just in case").
But if someone else can get some good use, let me know. I'll dust it off and send you details.
It is a commercial set up with flat 7 pin plug (no cable). Mounts up under the tail lights and doubles up off the Muffler bolts.