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...
Well, good news, the source code is right there. Someone can go check (it probably won’t be me)