Curator Response: Thanks for the report. The Waltham factory serial lists designate this run as a 6-Size, Model 1873, Seaside Grade. It is crucial to understand the limitations of original factory documentation which is known to contain errors due to company practices. It should also be noted that the factory serial lists indicate the first run of Model 1889 does not occur until 4,044,001-4,046,000, though an earlier run would not be surprising. An eBay item number would be beneficial to evaluate this particular example further. (You have also listed two different serial numbers in your report).