I've been documenting a recurring set of markings that appears on non-numbered Century-grade Seth Thomas pocket watch movements and have been treating it as a Factory-Assigned Tracking number based on repeated physical observations.

There is no surviving factory documentation that I'm aware of, so the conclusions are necessarily inferential and provisional.

I've laid out the full evidence, limits, and methods on my website, and I'd genuinely welcome informed critique or corroborating examples.

Seth Thomas Fan Space – FAT NUMBERS Page: Factory-Assigned Tracking

.

If you have previously documented a non-numbered Century-grade Model 10–13 movement and would like to share photographs for research documentation, the Image Contribution Form at this link may be used. You may copy the form into a document or email, complete it, and submit it along with your images.

Image Contribution Form https://www.seththomasfan.com/...-contribution-form-1