Relevant trademark records are discussed in Searching for the Beginning and Bulova Case Signatures.
1917 Dating a Bulova watch becomes quite a bit easier beginning with models manufactured in 1926.
Consultation with online movement lists may provide at least ballpark information regarding the date of the watch. However, it is important to note that all such movement lists are based on observations of examples rather than any official Bulova documentation.
So, the lists may be incomplete and even inaccurate to the extent that they contain information on movements that are not on-hand and available for examination and verification.
Though we have far more of these early watches than we did a year ago, we still have relatively few upon which to base conclusions.