I have seen a number of Tiffany PL wristwatch movements that were signed by C.H. Meylan and stamped with the US import code HXB. That was IWC's import code. I presently own this example. If you can shed light on the Meylan-IWC connection, I would be grateful for an explanation. I will post this message in the WW forum as well.
Do you have a date for the watch? I am no expert on this, but I thought the import codes identified the organization that does the import, i.e. the American entity responsible for it. Is C. H. Meylan currently a maker, or just a name used by whomever thinks they can get away with it? This looks like a very fine example to me. There is another very similar that I found that is 17 jewels and not quite as nice condition. It has the same import code.
Tom, the watch has a 1948 inscription. I collect C.H. Meylan PWs and information about C.H. Meylan. He died in 1916. PWs signed "C.H.Meylan" seem to have been sold after Meylan's death until at least the early 30s. Thereafter, at least a small number of WWs were marketed under his name. I don't know who owned the brand after Meylan died or whether his brand was used without authorization. I referred to the U.S. Import Code database on the Ranfft website. Ranfft Watches, US Import Codes. It says that the codes refer to the "Manufacturer, Importer, Brand".
I see that Ranfft explains this code with an italicized reference, indicating only one example. Based on some very old posts on the IWC collector's forum - Collector's Forum - it sounds as if the code may be for the importer rather than the manufacturer, and it is suggested the code may have been used by Henry Blank (Cressarrow). Blank is known for casing many imported IWC movements, and perhaps Meylan as well? I do not know if this early surmise has been further proven, but it may show that the only connection between IWC and Meylan is that they were imported by the same company. Is your case marked for Cressarrow?
Jerry, I think you've nailed the explanation. It makes sense that HXB would refer to Henry Blank. For starters, the C.H. Meylan wristwatch pictured in post one with the HXB stamp is in an 18k Cress Arrow case made by Henry Blank. So was another HXB-stamped 18k C.H. Meylan wristwatch I used to have. Further, lots of C.H. Meylan and IWC pocket watches sold in the US had Cress Arrow cases. Of the 44 C.H. Meylan pocket watches in my collection, 19 are in Cress Arrow cases (9 are in Jeannot & Shiebler cases, 5 are in A.W.C.Co. cases, and 13 are in cases by other makers). Of the 33 IWC pocket watches in my collections, 16 are in Cress Arrow cases (12 are in IWC case and 5 are in cases by other makers). I think of Henry Blank as a jewelry and case maker, but Blank also must have imported watches because quite a few of my Meylan movements bear the Cress Arrow trademark, and some are marked Cresarrow Watch Co. Cress Arrow PL'd IWCs are less common, but I do have one marked Cresarrow Watch Co.