Curator Response: Thanks for the followup. The Keystone Howards are certainly an area of active ongoing research, and we can expect more clarification to be revealed over time.

Curator Response: I agree that the damaskeening pattern appears to be different than on the #984761 movement. However, it is consistent with other Series 4 and Series 9 movements. The #984761 pattern is unusual compared to other movements.

Curator Response: From the images, it appears the meantime screws are gold and the remaining balance screws are brass, which would be consistent with the Series 9 designation. Though, analyzing metal tone in photographs can lead to erroneous conclusions. Having it in hand, you would be much more qualified to evaluate this trait.

Curator Response: Thanks for the report and images. Since the Series 4 and Series 9 feature the same damaskeening pattern and markings, it is important to analyze the other features. Interestingly, your watch has distinguishing characteristics of both the Series 4 and Series 9. While all known catalog descriptions of the Series 9 indicate the watch was only offered as pendant-set, the brass balance screws are generally considered a trait of the Series 9 after being downgraded from the gold balance screws fitted in the Series 4. Serial #991445 has been observed as lever-set as well, but the balance screw material is unknown. It is an important distinction, and additional examples will assist in better insight with this range. Since this production falls within the logical transitional period between the Series 4 and 9, I would temporarily consider it as a hybrid. I have noted your example in the research notes for future evaluation.