An amazing find and restoration of this very special 21CT55:
https://www.vrcmct.org/exhibits-collections
Scroll down to film and Television- there is a video and a button that will bring to an Essay that explains the acquisition and prominence of the set.
Just goes to show that they are still out there- hiding and waiting to be found-the donor was an off the grid 87-year-old RCA Engineer from the early 1960's whose Father was an Engineer fro RCA from the 1930's to his retirement in the late 1960's- He saw it all- All of the players were at RCA Princeton in the 1950's.
Enjoy!
Kirk