I too heard the story of using the radar for the approach to St Moritz from John himself (he had made some plates of the expected shape of the mountains and would compare the shapes on approach). He was once in a holding pattern with other aircraft circling above cloud at St Moritz, then commenced an approach. On seeing John descend into cloud, the other aircraft thought he had had an emergency and radio-ed distress.
He always went ski-ing at St Moritz.
Originally the P2 seat was removed to allow installation of the rather bulky Decca Nav - this long pre-dated the advent of GPS.
However, in later years John re-installed the seat as he decided the presence of a co-pilot was desirable. He was 92.
Altogether a long and remarkable flying time, a specialist on instruments.
flyme.