Seen in a 1935 ad - Duoettes v Duettes

In a 1935 ad for Coulter Dry Goods Company in Los Angeles. A drawing of a generic "Duette" type pin, described as "two clips that may be instantly transformed into a brooch...available in many striking styles". It is called a "Duoette Clip". No manufacturer or brand is mentioned, so perhaps a play on the Coro Duettes available at the time - or perhaps a misprint, since this was during the time that the Coro Duettes were being introduced.