The machine has not been used much since I acquired it about twenty years ago and had it serviced by the late David Lane, who was the go-to man for Nagra in the UK. I have run it up occasionally, and it seems to be working well, but I can't rule out the possibility of the odd gremlin having arisen through disuse. The button for the headphones mono push switch has disappeared, but the machine is otherwise complete and unmolested. Even the ganging toggle for the gain controls is present and correct!