Some more thoughts and questions..............
1) I was talking with
@CafeRacer about HPC since he did a post on IG about it recently, and he mentioned there appears to be a date transition from early (spelling full name Henrique Pfeffer Caracas) to late (abbreviated HPC if that is indeed what it stands for). He didn't recall the exact cut off or have the data on hand so I wanted to have a quick look around online and see what I can find.
From my limited searches here on OF and on the internet, this is what I have in about an hours research (please excuse, could by slightly sloppy on some of the digits, I was highly focused on the first 3 digits of the case serial for dating purposes):
EARLY (Henrique Pfeffer Caracas)
753XXX - 212205
908XXX - 1XXXX
977435 - 22276
1007496 - 212205
1011001 - 212143
101156X - 212144
104XXXX - 12322
LATE (HPC)
1090443 - 20724
1107160 - 22242
1379XXX - 12445
14921X2 - 206503
1492310 - 206503
1664061 - 106515/1A
1666585 - 122100/1
So that's 14 examples and so far they appear to sort quite neatly into a consistent pattern.
It would be good to add more data and see if anyone can confirm or contradict the above pattern?
2) is anyone aware of any Henrique Pfeffer Caracas branded boxes, papers, etc? In other words do we have any examples (either fully spelled or abbreviated dials) with some supportive accessories?
3) If there was a company switch from fully spelled to abbreviated, was that only on watch dials, or would that have been reflected in other merchandise? In other words can we find other products that say HPC ?
4) if HPC does not stand for Henrique Pfeffer Caracas, and instead is High Precision Certificate or the like, then theoretically we should stand to find some Henrique Pfeffer Caracas dials that ALSO say HPC. In other words why would Henrique Pfeffer Caracas never sell a single example of a High Precision Certificate watch from among all their watches? But I've never seen such a thing.
5) Lastly, I came across an article on the dink about a collector that has two same time only reference, one is signed HPC and one is not. In this article they state that HPC stands for Henrique Pfeffer Caracas. So I wonder where does their information come from (maybe the collector?), or did it come from here on OF, or have others independently come to the same conclusion, etc? I guess we could reach out on IG and ask.
https://www.hodinkee.com/articles/jojo-la-montre-joel-laplace-geneva-vintage-watches