It would probably be nigh onto impossible to do much at all if not for eBay, where dedicated researchers can observe and record case numbers (and associated movements and/or inscriptions) from more cases than we would have seen in a lifetime, before eBay. Also, the dates are linked to movement serial numbers, not case serial numbers.īecause of the nature of the case business and other aspects mentioned by Kent it is slow, painstaking work to begin to reconstruct some of the case manufacturing histories from observation of surviving cases and limited vintage catalogs and advertising. However, this is only very approximate and may have errors. Movement Data looks at the dates inscribed on the cases of watches having similar movement serial numbers.

The Encyclopedia article entitled ' Keystone-Howard Case Dates vs. To my knowledge, this data has yet to be published. date data for a very limited number of factory-cased, 1920s-plus Illinois, Hamilton and perhaps Ball watches. Having stated that, there are limited instances of collectors having gathered case serial number vs. Also, there do not seem to be any surviving records from watch case companies linking case serial numbers to specific cases, their grades, sizes and etc., nor are there tables that relate the case serial numbers to dates. Thus, there were no published lists of case company serial number vs.

On the other hand, the function of the case serial numbers seems to have been for internal uses only, primarily to keep the major pieces together during production and to track the disposition of expensive materials and finished product. While movement serial numbers were used to assist in, and track, production they also needed to be maintained and published for the purposes of movement grade identification, primarily for the obtaining of correct replacement parts. Although a lot can be learned about many American watch movements by knowing the movement's serial number, the same cannot be said about case serial numbers.

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