Interesting fact: Did you know that german market MB5 & MT5 were not fitted with a horn?

Instead they had a bell fitted to the handlebars

(you can just see it under the right hand mirror (silver disc) on the MT5 above) 

This is an actual bell taken from a German spec MB5

And just to prove this is not a wind up! note lack of horn button!

All the above pictures kindly provided by Tilo!