Split-seconds (rattrapante) are one of the most advanced wristwatch complications, and vintage split-seconds offerings are exceedingly rare. In this section we delve into the Breitling Duograph, a family of split-second wristwatches first produced in 1944, building upon the release of the Premier the prior year. The Duograph family is comprised both the two-register references 762 (non-waterproof), 764 and the 783, as well as the three-register references 766 (non-waterproof) and 791. The two and three-register references utilize the Venus 179 and Venus 185, respectively. This survey includes all combinations of case material, stainless steel and gold, and pusher design, both rectangular and round. 
I have found just over a dozen of the most common Breitling Duograph references, and only a handful of the least common. Of these, I have found an extremely high percentage of Duographs that are not in original condition, with swapped hands, dials, cases, casebacks, movement parts, and crowns. While a curiously high number of Duographs are a mixture of components from different timepieces (Breitling or otherwise), with figures so low, it is difficult to say with certainly what attributes are original to a specific piece. However, when we look at the set of known pieces overall we can see when watches do not appear correct – hand design or color, dial, case, movement, and so on.
Given such low production volume of the Duographs it is possible that we see attributes only on a single watch. When making purchase decision, you should consider whether you feel comfortable in how it compares to others known, and, if you may resell it one day, will you have to explain any, ahem, “unique characteristics” of the watch (I prefer not to have to do so).