Your premise is faulty. First and foremost the name TK-D was not adopted until 1955 and then it was developed in the 29th infantry division of course populated by TSD practitioners like Nam Tae Hi and Han Cha Kyo. So., exactly how many TKD Schools (Not TSD) do you think there were in the 1950's?So, If one trained in a TKD or TSD school in the 50s would have been largely indistinguishable.
What schools were teaching TKD outside Korea in the 1950's ? Where and by whom? Have you spoken to any of these TSD or TKD instructors from the 1950's or is tis simply something you have concluded from internet snippets?