You'd be surprised, I saw a similar (the same?) model pop up on ebay a few weeks ago. Some rare and special pieces can be advertised in quite normal places - Ebay, watch forums etc.
You've just gotta be on the lookout. If a rare Heuer pops up on ebay as a buy-it-now, chances are someone on here will have it pretty darn quickly, of course if you don't see it, you won't see it.

I spotted a bargain buy-it-now on Sunday on ebay.. by the time I cross-checked photos to make sure it was all in order, it was sold.
You've gotta be quick!

Stewart

: Where does one find such beauties?
: I assume it's not in the usual online places
: Very curious