The Miccosukee tribe became a Federally recognized independent nation in 1962. Prior to that, it was part of the Seminole nation. So technically, Harry Billie is not a Seminole, other than being an alum of Florida State.
Harry Billie did fairly well with the Pirates' organization, rising to the Bucs' spring roster in 1965. His minor league record is at:
https://www.baseball-reference.com/r...d=billie001har
The photo below is from the Pittsburgh Press of March 6, 1964. I can't find any evidence that he was in the major league spring camp that year. They were trying to groom him to be a catcher in the minor league camp.