An unknown, fifth (chronologically first) dub of Dragon Ball: Curse of The Blood Rubies may have been done by the Tokyo dubbing company Frontier Enterprises. This is based on comments made by Frontier voice actor Richard Nieskens, who previously listed it on his LinkedIn profile (albeit he erroneously refers to it as Dragon Ball Z). Given his comments in an interview, where he states it was done around 1987, and given Frontier's dubbing activities at the time, that likely means it was the first movie.
The LOST Dragon Ball English Dub BEFORE Harmony Gold (Frontier Enterprises, 1987)
LSuperSonicQ’s video on the subject.