This Dimosil derailleur seems to be associated with the Caloi 10, an iconic Brazilian drop-handlebar ten-speed in the classic 1970s style (can you hear the rattle of that chromed dinner plate spoke protector?). These Caloi ten-speeds seem to enjoy cult status in Brazil - and they are so strikingly horrible that I can easily understand why.
The Caloi 10 was launched in 1972, and was probably originally fitted with a genuine SunTour Honor. However rampant Brazilian inflation and bizarre exchange rate movements took their toll, and a cheaper Caloi Sprint 10 was launched in 1979 featuring locally manufactured components. I suspect that this may be when this Dimosil (1st style) made its appearance - it is certainly an alarmingly faithful copy of the SunTour Honor (4th style). Dimosil had good taste, the SunTour Honor was the inexpensive gear of choice in the late 1970s.
Combine good taste with the fantastically inept management of the economy that is the hallmark of neo-fascist-soldiers-who-think-they-make-great-leaders, and you get a decent, if unspectacular and slightly out-of-date, locally produced derailleur.
Can it be long before some little known company in Hugo Chavez’s Venezuela produces a serviceable copy of a model year 2000 Shimano Tiagra?