The code was +KU with the U letter overpainted.
Attachment 11413
The factory code was SO+FN for the Ju-87 G-2 t6+KU
And The factory code was KT+RJ for the Ju-87 G-2 t6+FU
t6 SG2 code was invisible for the both aircrafts.
I didn't see the U letter for FU. Maybe it was very overpainted.
Best regards,
Lumabe.