Spotted this week in Vienna, a customised Horex. I know nothing about the marque (never imported into this country, I'm sure) but I'll guess it’s a Regina 350 or 400 from the early/mid '50's - stripped down and fitted with MZ forks and front disc brake. Just the thing for a Viennese hipster.
Horex produced bikes from 1920-60. The name was from the town of manufacture, Bad Homburg in Germany and Rex, the parent company. The name was revived in 2010.