Ultraman Leo was a series that followed in the line of the popular Japanese Ultraman series, each season would see a new successor to line. Leo was the last Ultra series produced in the 1970's.
According to Super Collectors Guy Redwing and Ed Weinstein the figure was released in 1974 by the company Miura Toy and there is belief that there were more figures in the line. Miura Toy was not known for action figures.
This figure is missing a chest piece, if anyone has it please contact the Museum for a cash reward.
Up until recently this figure was legend, only appearing in a tiny pic in an Japanese book( courtesy of Imp).
The dolls blue shorts are as Mego as his type 1 body. The whole suit and doll concept apes the then popular takara Henshin Cyborg series.
According to the good folks at Kimino My House,is that all that is "supposedly" known is that there were possibly three characters produced. All the characters were quite minor and from different TV shows that were popular at that moment. Possibly Kamen Rider X was another figure.
That would maybe explain who Mr. Red Shorts in the picture below (photo from the collection of Guy Redwing)
Many thanks to Guy for his terrific input.