Okay, here's a complete batch of all the subtitled and dubbed episodes known to exist as of February, 2020. A few days ago I posted separate batches of subtitled and dubbed episodes, thanks to Cavery for letting me know that there were actually a lot more dubbed episodes available than I had been aware of.
It's the 1965 TV adaptation of Osamu Tezuka's classic manga, from Tezuka's anime studio Mushi Productions. Some time around 2011 I subtitled episodes 1-3 and 7 of Wonder Three. If memory serves, I think I chose those episodes because they weren’t known to exist in the English dubbed version. Then the US streaming rights to Wonder Three were bought by this new company called Anime Sols, so I put my episodes on the back burner and they never got released.
There’s no need for me to re-hash the details about what ended up happening with Anime Sols, there’s a pretty good ANN article that covers it here: https://www.animenewsnetwork.com/answerman/2016-04-11/.100897 The site was started by a talented anime translator with some interesting new ideas on how to get anime licensed and distributed in North America, but in the end the venture didn’t last all that long. It did result in some shows getting crowd-funded DVD releases, and they did stream episodes of some amazing old shows.
Sadly despite all of the cool shows that they streamed with English subtitles, Anime Sols only ever got around to streaming the first three episodes of Wonder Three. I did eventually release episode 7, and then later followed up the project with episode 4. There didn’t seem to be any urgent need to release the first 3 episodes, since rips of the Anime Sols versions were still floating around. Since we’re at the start of a new decade I’m trying to do a bit of housecleaning, polishing some older subtitles of mine and finally releasing some stuff that’s been languishing on my hard drives for years. Thanks to Cavery I can now include an even bigger batch of the dubbed episodes as well.