Late to the party. Hope you haven't returned them ?!
My take on this anyway:
My own set below looks like yours - 16 stamped on a angel. Ridge below is there, but faintly. My set is from an early 165.024 with early 1506 bracelet stamped 3/64.
I have seen a few others and IMO correct examples of the angled 16. One here for instance:
Again on a 64 bracelet, here on a 105.012-63.
So even if most 16's are stamped horizontal, I do think these angled ones are correct and seems to be an
early version. Nothing about the angled 16's indicates repro or fake in regards to quality and stamp etc.
And
if fitted on 64 production 20mm speedmasters and SM300's, that would explain the low numbers seen, as the 165.024-63 and 105.012-63 (64 production references) are pretty scares by all means.
Well, just a few cents...
