Just for reference - I would like to add another Hexar service contact I heard of: I recently received another recommendation for a Konica repair technician in Munich, which I can't back by any experience of my own (YMMV): Reiner Muchel, Agnesstr. 18 in Munich, Tel +49 (0)89 - 2727 3489.
His name was mentioned in the mega tread about the Hexar AF on photo.net (going for 14 years, and still scoring new page hits). Since a lot of Hexar users are likely to follow the thread over here, I feel that this service person ought to be mentioned here as well.