The Omega S.A., now a part of the Swatch Group, is well-known for its wrist watches. Nevertheless, the company made a large number of pocket watches. In addition to the Swiss-sized, cased movements, a series of movements, sized to fit American cases, were exported to North America.
Omega pocket watch movements were made in sizes to fit standard American cases, as stated in a number of ads, an August 1898 ad and an April 1908 Ad serve as examples. At first, Omega watches were distributed in the U.S. by several jobbers, firms known for importing other lines of Swiss-built watches. However, by the beginning of the Great War, Omega had apparently set up its own distribution company, United States Agency - Omega Watch Co..
One high grade Omega watch, a 16-size, 21-jewel movement which lacks a grade identification, is lever-set, is fitted with a precision, Nautilus regulator and is marked to have been "Adjusted - Five Positions." Not having the maker's grade name or number clearly visible on the movement probably prevented it from being suitable for railway time service. The markings "Omega Watch Co. Swiss" on the movement and "Swiss Made" on the dial indicates that its traget market was probably the United States although nothing would have prevented it from being sold in Canada (see below).
Omega supplied a number of pocket watches for Railroad Service World-Wide, but the watches accepted into North American railway time service were required to have a higher number of jewels and a finer finish. To compete in this market, Omega produced several highly-jeweled, lever-set Movement Grades (CCR, DR, CCCR & DDR) in both 16-size and 18-size, and in open-face and hunting-case configurations.
Those watches sold in the U.S. were marked Omega and the word "Swiss" to conform with U.S. federal law. However, Omega railroad grade watches sold in Canada (the exact same grades as were sold in the U.S.) were labeled "Ls. Brandt & Frere, S.A." and lack the "Swiss" marking (clearly indicating that they weren't intended for sale in the U.S.). This has been widely observed, but never satisfactorily explained.
One supposition that has been mentioned, but for which there is no supporting documentation, is that most of the Canadian watch inspectors* were not part of the Omega distribution network. Thus, there would have been little opportunity to sell Omega watches to railroaders since they frequently bought their watches from the watch inspectors. However, Omega's marketing agreements with their dealer network prevented Omega from selling Omega-marked watches through the (non-Omega dealer) watch inspectors.
* Watch inspectors were mostly local jewelers, appointed by the railway's time service authority. They received a nominal fee for certifying standard watches and performing regular inspections (either twice monthly or every two weeks). The main advantages of being a watch inspector were the opportunities to sell high grade (expensive) watches to the railroaders and the constant traffic of those railroaders who might conduct their other jewelry business with the watch inspector while they were there for the regular watch inspections. See the Railroad Time Service Encyclopedia article.
* Omega memo:
From: Departement: Controle Central de Fabrication
Bienne la 16 Fevrier 1970
Concerne Annees de fabrication
It seems that, like Hamilton and, to some extent, Hampden and Seth Thomas, Omega may have pre-assigned huge blocks of serial numbers to different models or grades. This would account for overlapping series' of numbers, spanning a range of years.
The early serial number vs. date data seems inconsistent with an 1899 ad which proclaims that (at that date) there were over 1,000,000 in use.
There don't seem to be any North American railroad watches in the 1,000,000 series or 4,000,000 series and there are only small groups of North American railroad watches in the 3,000,000 series or 5,000,000 series. The bulk of the North American railroad watches seem to be between 2,360,000 and 2,600,000.
According to a conversation with Kathy Pritchard at the 2005 Ft. Lauderdale NAWCC convention, Omega bought out Regina in about 1912. After that point, Omega marketed a lesser grade of its watches in Canada under the Regina name. As examples, Doug Sinclair once posted a picture of 15-Jewel Regina Movement, and Grant Perry posted pictures of the 17-jewel Movement and Private Label Dial of another. Some of these Regina-signed watches were Adjusted Highly Enough as to be suitable for use in railroad time service. These appear to carry Omega serial numbers consistent with the serial numbers applied to their Omega-labeled watches.