At least the 2nd one I've seen like this, possibly the 3rd. Serial number was around 21.xxx if I remember correctly, it was an SRC and obviously the rotor is not the common brass rotor. Looks like some kind of repair was made at the back of the rotor on this one.
Was at the Fest. I know we've mentioned these once or twice in the last 9 years or so, but don't think we've ever had pictures of one.