Thomas,
What are the 1950-60s speakers in the last video you posted? I am not familiar with them.
Opening of Audeum Museum
https://www.audeum.org/home
Mr Chung of Silbatone had built Audeum Museum in memory of his late father with budget of 150 M USD.
I attended opening ceremony on May 30th, 2024. Mr Chung gave speech.
Mr Chung gave explanation of the system. This one is Western Electric 16A and 16B.
They also display rather new vintage speakers dated 1950-1960.