Josef Reif went for a drink with colleagues in a wine bar after finishing at the opera on Wednesday night. He put the instrument at his feet in a silver-gray Samsonite backpack that looks rather like a laptop bag. When he looked down, the bag was gone. Auf Deutsch here.
The horn, valued at $8,000, is registered with a serial number and is a Vienna-style instrument, easily recognised. Reif has alerted all stores in the city. It is probably unsaleable in the locality. Keep an eye out for it online. Josef is in great distress.