Hi guys I have seen a Heuer Ref. 13-1 for sale locally and was just wondering about the rarity / collectability of this model. I am not usually drawn to PVD watches however this one just seems to keep popping into my head. I see it listed in the 1979 catalogue on OTD however cannot seem to find much other information save that it is powered by the Valjoux 7765 movement. Any help is greatly appreciated.