Here we see Chaluret advertising a derailleur called the 'Huret CP 83'. We might confidently speculate that 'CP' is a contraction of 'Course Pro', the model name of the 1936 and 1937 Huret models. These, earlier models were manufactured, for Huret, by Chaluret. As Chaluret is actively advertising the 'Huret CP 83' we might also speculate that Chaluret manufactured this fine device.
Some time shortly after this advert for the 'Huret CP 83', Chaluret and Huret parted ways and Chaluret launched their own derailleur called the 'Chaluret 93'. This leads me to a spurious theory about the numbers '83' and '93' in these model names. While I was a student, I had a holiday job in a, very old-fashioned, factory making machine tools. They named their models by the year of introduction, but, cunningly, reversed the numbers. So a model launched in 1973 would be called the 'Model 37'. They did not name it the 'Model 73' because they feared that, on the 1st of January 1974 it would instantly look as out-of-date as it really was! I have a strange hunch that Huret/Chaluret may be playing the same bizarre game and that the 'Huret CP 83' may have been launched in 1938 and the 'Chaluret 93' may have hit the market in 1939. As ever, this is merely entertaining speculation.
As for the question of what the 'Huret CP 83' derailleur might actually be, my guess would be that it was an iterative evolution of the Huret Course Pro series. I guess this because of the name and because it seems likely that it was also manufatured by Chaluret.
(Source gallica.bnf.fr/ Bibliothèque nationale de France)