Like Jeff, I have never seen one quite like this either!
Jeff points out the longer markers, but the serial number puts it at a time when the Carrera was using the markers with inserts so even more unlike its contemporary Carreras. The Tachy scale is also unlike those that Heuer used on either execution of first gen Carrera (but one I think I've seen before, just can't picture the manufacturer right now :/ ) so it looks like Valjoux went to a dial manufacturer independently of Heuer for this watch. It might not even be Singer, would be interesting to take a look at the dial reverse when it's next serviced and see if there is a manufacturer's mark. The hands are generic hands rather than those from the Carrera too, possibly even the ones supplied by Valjoux before manufacturers put their personal touch on them.
And the movement is marked, just where you'd expect it to be for a Valjoux demonstrator - on the baseplate under the regulator, where the mark usually is for Valjoux. Bridge markings were usually done for the watch manufacturer, so I'm not surprised that a watch to be used by the movement manufacturer would have an unsigned bridge. After all, Valjoux are presumably using the watch to show and sell the 7736 to other watch manufacturers and would hardly want to be advertising Heuer to them in the process!
You'll get that I'm agreeing with Jeff that this is a salesman's watch, what I'm calling a demonstrator. I'd reckon it was used for showing to prospective purchasers of the movement, i.e. other watch houses, hence the unsigned bridge and Valjoux dial. Quite often the dials are just sterile for these demonstrator watches, it's quite nice to have one marked with the Valjoux symbol, they obviously went to a bit more effort to have the dial commissioned. The serial number fits in well too, the 7736 movement was new in 1969 and it makes sense that Valjoux would be hawking it around to the watch houses in that sort of timeframe.
The watch community in Switzerland was pretty close-knit so any demonstrator showing this watch wouldn't have to travel around too much. That means there probably were never very many examples - maybe more than just one given they went as far as commissioning a dial, but probably only a handful. Of course, we could be wrong that it was a salesman's demonstrator watch, and Valjoux may have made some available for general sale, which would mean more were out there but this is the only one I've ever seen and it being a demonstrator makes for quite a convincing argument, I think.
