The Adventures of Gamba (lost English dub pilot of anime series; early 1980s)
From The Lost Media Wiki
In the early 1980s, TMS Entertainment (then still known as Tokyo Movie Shiensha) made a dub of the first episode of "The Adventures of Gamba"
The dubbed episode failed to sell and it was last shown at the C/FO (Cartoon/Fantasy Organization) convention but was snubbed because C/FO was only interested in giant robot/mecha anime
The only evidence of it's existence is on a comment on Cartoon Reserch's article on the anime by anime historian Fred Patten
Link to article: http://cartoonresearch.com/index.php/the-adventures-of-gamba-1975/