Check this out. On initial check it seems like a possible legitimate piece but when you look closer the area on the dial behind the 'BREITLING' appears to have been scrubbed or modified to remove whatever name was there originally. That plus the lack of a corresponding serial number and Landeron/Hahn lever movement would make most hesitate on this one. The unaware need to be careful out there.
https://www.ebay.com/itm/Unusual-and-Rare-Vintage-1920s-Breitling-One-Button-Chronograph-Original-Dial/392277689319?hash=item5b559283e7:g:7w4AAOSwQKdctNVG
