Holy cow !!!! Have you reported to the police? I still dont think they would take the paint for analysis (unless you know some high seated cops).
I'm usually not wishing anyone but theres a limit... feckin arsehole.... if only she/he would stand to what she/he done.
I really believe Ducati NA stands to their promises and help you make her runnin again.
Just a thought - maybe that was someone that was attending the very same meeting? Matbe its worth asking a bit around with people you met there (whos got such a car etc?)