Archive.org now has a page with "the raw analog waveform and the reconstructed digital tape image (analog.tap), read at the Computer History Museum's Shustek Research Archives on 19 December 2025 by Al Kossow using a modified tape reader and analyzed with Len Shustek's readtape tool." A Berlin-based...
Have you read Unix: A History and a Memoir? I only started it, but the first chapter or two is just Kernighan talking about Bell Labs.