H D6928 built in spring 1993, Corsa Extra frame, Mx Leader fork.
Repainted with M9B pattern used since 1998 (this is not GAN)
New SLX was not used then.
Unusual is the lack of X-marking (surely this is Columbus?) and the frame +fork combination.
I saw something like this only in profi team frame (Telekom)
Markings on the steering tube?

H4X 4258 - This is a 1992 Corsa Extra SLX, the "EMC man" forgot the letter D