The original Latin American theatrical dub did not voice over the crawl. I’m not sure which crawl they used (Castilian or localized Latino), but at least one of the prints scanned by the 4K77 team was actually a Latino print. I know this only from the audio captured, I don’t think I ever saw the original scanned crawl itself. This may have changed for the later dub made for the Special Editions, which is on Disney+, but I don’t know much about it.
There is no evidence of a Portuguese crawl for the unaltered films. It’s possible one was made for some iteration of the Special Editions. Brazil’s first dub was for TV broadcasts, and I don’t think there was a theatrical run there until the SE. There was never a European Portuguese dub – Portugal is one of the countries where dubbing is very rare except for children’s programming.
So, Star Wars did, in fact, get an original theatrical release in Brazil in 1978. Little is known about if any dub was used or not. I also think there wasn’t any crawls made specifically for Portugal and Brazil. The wide translations only came by the time of the Special Editions.