Hello,
These aircraft are not Ju 88 A-6 or Ju 88 A-6U as these are Ju 88 A-4 (and some D-1, besides many A-17´s) fitted with FuG 200 radar.
The A-6U designation is fiction, invented in the 1960s, and has nothing to do with Radar equipped Ju 88´s.
In fact Junkers did not use /U for any conversion, as engines were the ruling factor, after design purpose.
Proper designation for these shown is Ju 88 A-4/D (Rustgrad D, or Equipment condition D).
The A-6 (and A-8) reverted to normal A-5 (and A-4) after Heavy fenders had been cancelled.
They simply remained A-6´s (often referred to as A-5s in losses.
Best regards
Eggert