Viscounts from Lufthansa
WHBM
The 4 Viscounts that you mention, although originally delivered to LH, were actually purchased from Nora Air Services (NAS) who were based at Kassel-Calden, Germany.
I seem to remember seeing one at EMA in NAS scheme.
Did NAS also operate Nord Noratlas aircraft, presumably as freighters, or is my memory playing tricks?