Focke-Wulf Fw 200 C-5 and C-6
The murkiest part of the Condor story is that of the C-5 to C-7, with many sources claiming that they didn't exist.
This appears to be the best current research on these aircraft, but may not be entirely accurate.
The C-5 was mostly a reworking of the armament of the C-4, and now including the Loft 7D bombsight as a factory fitting. The addition of extra weight in armour and fittings at the D-stand at the rear of the ventral bolas led to the tailwheel retraction mechanism being deleted to keep the aircraft in balance.
The C-5/FK aircraft were, like the C-3/U7, modified as test aircraft for the carriage of the Hs 292 anti-ship missile. And similarly, they ended its life as a transport.
The U1 is a strange fish. The design for the U1 called for an up-armed C-5 with a turret at the dorsal B-stand. Only one aircraft was built and it was famously shot down by a USAAF B-24 Liberator and crashed in Spain. At this time it was configured as the prototype for the long-range reconnaissance C-7 model, with the B-stand gun position blanked out.
The C-6 designation appears to have been applied at least 3 times, possibly including a trial of rubber de-icing boots in 1943.
The final design for the C-6 fitted an improved version of the A-stand turret. However production of these turrets was slow, and finished turrets were diverted to the Junkers Ju 290 project. As such most C-6's may have been initially completed as C-5's.
The trend of using current production versions of the Condor continued with the U2 version being created as a modernised replacement for the C-4/U2, using the same turrets as the C-4/U2. Additionally at least one combat C-6 was modified to passenger transport standard.
A single C-6 was modified as a test aircraft for the FuG 224 Berlin A radar, which was a reverse-engineered copy of the British H2S radar.