I think I've seen 3. Only one made it to the area as prize support (he was a prize before the prize packs were the same for events and only one venue got him for the event). The Battlemaster for that event is a completist and he ended up getting one by trade or purchase. Plus, I ended up with one. That's all I'm aware of.

It's perfect to ram things with style if you're luck enough to hit (someone said this before).

And it belongs to Eridani's Light Cavalry.

I personally have two rusty's. One in my collection sealed in his box, and has only once seen the light of day. The other is in my play box, and once in a while terrifies opponents. I even used him last night, we had an unrestricted 1000 point single faction with no more than 2 of any unit three players to a table tournament. That 4" radius is nice.