Nice to see I was consistent this time and last though, in thinking that there is probably something in the case references. It will have taken a Franken maker a fair amount of research to come up with a viable, otherwise unused model reference so that's a fairly compelling, if not decisive, vote for originality. Lots of fakes and Frankens either simply omit the reference and serial, or use ones out of kilter with known genuine Heuer ones. Of course, Heuer themselves sometimes throw numbers out of leftfield but it can be a useful indicator when researching watches.