This derailleur is a nasty piece of work. The gauge of steel used throughout is too thin for the job (even the hanger plate is 3mm thick - Huret use 3.5mm) and it has bent in a thousand places, the plating has a terminal dose of leprosy and every opportunity to lack precision has been grasped with both hands.
Perhaps out of embarrassment at its shortcomings, there is no branding on any of the plates. One of the bolt heads is branded as ‘MELFRA’ - but my suspicion is that this may be a brand of bolts rather than of derailleurs. The internet reveals that a company called ‘Industria de Parafusos MELFRA Ltda’ exists to this day in Sao Paolo supplying basic steel products like bolts.
Despite all this criticism, this is an original derailleur design, and it has some virtues - in particular the placing of the adjustment screws is remarkably convenient for a ‘flat plate’ based derailleur. In this respect, it has more in common with a Shimano Pecker than with a Huret Svelto.
This ‘3rd style’ differs from my ‘2nd style’ version in having an unthreaded hole where the cable outer stops (indicating that there is no adjustable cable outer stop), and different shaped cable clamp washer and a fairly conventional Huret pattern hanger plate design.