Yesterday I found this button showing a crown with 5 points. Do you have any ideas about the origin and the age of this button. The inside legend reads "Extra Fein".

I will answer in German:

Typischer Livree-Knopf mit Krone des untitulierten Adels (5 Zacken)

"EXTRA FEIN"-buttons are approx. between 100 and 150 years old.
Attached photo is from: Walter Hostert "Geknöpfte Heraldik"

Greetings  

@Stratocaster: thank you for your help!!!