Cool watch, Tom! I find ads for 2 models in this case, but both are 17 jewel and dial per ads doesn't match - Sponsor & Broadcaster.
Broadcaster is advertised as rose gold, but seems to have 3 variants, "A, B and C", and Sponsor assumed to be yellow gold. We have IDed this watch with 21J Jewel as opposed to ads stating 17 and full numbered face as Sponsor - tentative, but also as Time King, like this one. I have yet to find ad confirmation, and don't know where the original "TK" ID came from.
So far I think we have 3 , all dated 1941 ID'ed as Sponsor/tentative (identical to subject watch) noting jewel count / face discrepancy, and 3 as Time King. Two are identical to subject watch but with no ad and this one that appears to be a redial to black with 17 jewels and face configuration matching Sponsor/Broadcaster ads.
Isn't this easy ? (insert eye roll here)
The more I look, the less sure I am that this model is indeed Sponsor due to jewel count and different face. Is the Sponsor ad wrong, and showing a Broadcaster, as we have yet to see one that truly matches the ad?
Call it tentative Sponsor, or revisit Time King? Panel thoughts?