You need the Japanese raw episodes. The best source is the (Region 2, Japan). You can find these on Amazon Japan or Yahoo Auctions. They have no subtitles.
Finding a complete English-subtitled version of the original 1969 Tiger Mask tiger mask 1969 english sub work
Keywords used: tiger mask 1969 english sub work, Tiger Mask 1969, English subtitles, fansub, Toei Animation, Naoto Date, Triple-Star Subs. You need the Japanese raw episodes
Unlike English-speaking territories, the series saw significant success in other regions through dubbed versions: Tiger Mask 1969
There is no licensed US/UK DVD or Blu-ray with English subtitles.
: The show was also localized in various other languages, including a Swedish dub in the 1980s.