Vietnam may not be the best place to search for vintage VCs. If yoy are sincerely interested, you may have to look at other markets to conduct your search.
The proportions look all wrong - font sizes and weights - bezel to lug and crown proportions. Everything just looks off. Especially the size of that small seconds subdial. Of course, this is all subjective on my part. It just doesn't look like a Vacheron to me. A Vietneron Consthanoi, perhaps. (In other words, maybe a locally-made fake?) Would be interesting to see the movement. It sounds like Dean may have seen this watch and or poster somewhere else already?
just review the OP's previous posts.