I did ask the official Koga dealer. Unfortunately, he has no clue about decals, but he promised to ask the factory on tuesday (shop closed on monday; so no answer before tuesday. )
Asking Kogo is no option; they have no e-mail adress available for end-user customers. All questions should be pipe-lined via an official koga dealer.
I would have liked to transfer these decals this weekend; so I hoped to read an answer by a "decal guru" here. Guess I'll have to be patient, though.