Arvor is a Breton word, meaning something like "people of the sea, sea folk", which the Bretons use to refer to themselves.
Like Pirofa the Arvor brand hails from Nantes, and Arvor & Cie was owned and run by Alexandre Ducoudray from 1948 to 1975. M. Ducoudray was also the travelling sales rep, visiting jewellers all over France. He also sourced his watch movements "from the Swiss border". Arvor in the 1950's and 60's had a reputation for producing watches of better than average quality for their target market.
Again like Pirofa, Arvor is now registered to Michel Cedric Epenoy in Morteau, who also has another old brand registered to him, Rulcy.
Although the Doubs region of France was the area that the French watch industry was concentrated in, it seems to me like every large town had, at one time or other, an assembler producing watches locally for his neighbours.
From its early days here is an Arvor from the early 1950's with a Femga 500 15 jewel movement, which is not featured in Rannft.
And now, one of the very last of the Nantes Arvors, from around 1975 with a FE 140-2C
With around 20 years between these two examples it shows what the now often slightly maligned, and certainly often overlooked, French small maker/assembler actually managed to produce in this era.