I too was surprised to see this one come up for sale and its a rare beauty. I know of 5 examples, two have been found in the wild and posted on OTD by the original owner. I also found a lone dial some years back in an Australian watchmakers parts bin. A search on the forum will reveal that find as well as the two mentioned previously.
Someone could have a special Chrtismas present (to themselves)
regards
Paul
www.heuerworld.com