My father owes Kudelski a great deal for helping him get critically important ethnomusicological audio recorded and preserved for his PhD. Two reel to reel Nagras were used in the most harsh conditions in the jungles of New Guinea, in the Sepik River during the late 60's to mid 70's.
These machines performed flawlessly and produced stunning recordings. I was recently involved in digitising them all for electronic publication some 30-40 years after they were recorded, while playing them back on the recorders that taped them. All in top condition, STILL. Music of the Ancestors: A Study of the Traditional Instrumental Music of the Iatmul of Papua New Guinea.
This is why I am a Nagra fanboy.
May he RIP.