Yes, this is the watch in row F-5 of our new Carrera table : http://www.onthedash.com/docs/CarreraReferenceTable.htm

They do seem pretty rare in their Calibre 15 configuration. The 1974 catalogue has debuts for this Carrera case with both Calibre 12 and 15 movements, but while we see the Cal 12s again in 1975, '77 and even as late as '78, we never see the Cal 15s again. Ok, not all watches that Heuer produced made it into the catalogues, but it certainly seems 150.573s had a shorter production lifespan than the 110.573s. I certainly see them much more often with Cal 12s.

The Côtes de Geneves dials are indeed fascinating, watching the light play over them is always fun!

My champagne and fumé Cal 12 versions say hi:

You probably won't see them often either, so if you've seen one you like, my advice would be to grab it while you can.

Mark