A watch dealer tells me that there were / are substantial differences in the 72 series in terms of plating, machining finishing, etc. Not just cosmetic stuff but actual tooling and specs. My watch maker says not really. Anyone know the reality?
I would trust your watchmaker over a dealer, who probably hasn't seen quite so many 72s (out of production since the early '70s, no?)...
Some info here: http://chuckmaddoxwatch.blogspot.no/2005/12/valjoux-72-chrono-family-discussion.html?m=1