Mystery Sealed Attenuator 1967 vintage 600 ohm Comes from Langevin Board

[1dddream]

Hello, and thank you all in advance.......
I have a significant collection of vintage sealed 600 ohm mid 60's attenuators
I have great pics to share via      [email protected]
They do not have a specific brand name on them, and I need to know their origin
They were in stalled in the custom Langevin Console at the Johnny Carson sound-stage in Burbank circa 1967 This was a no expense spared 1 of a kind Console { I have most of the board it is incredible}