Perhaps from Amts- + simile (from Latin simile (“similar”)), the name of a standardized form used by the bureaucracy of the Austria Empire. Alternatively, perhaps a reference to the service horses (Amts- (“official”) + Schimmel (“white horse”)) which were provided in Switzerland and elsewhere to government officials.
Amtsschimmel m (genitive Amtsschimmels, no plural)
- excessive amount of bureaucracy; red tape
- Amtsschimmel in Duden online