Hello Ivan, I can give a suggestion on the history of the firm of Imhof
& Mukle at Voehrenbach, Badenia. There is an association at Voehrenbach
who have special interest in those instruments. They call themselves
'Heimatgilde "Frohsinn" e.V. Vöhrenbach' and you will find information
and contacts at

http://www.heimatgilde-frohsinn.de/impressum_kontakt/index.html 

For the builders of orchestrions refer to (sorry, available only in
German):

http://www.heimatgilde-frohsinn.de/abteilungen/ak_stadtgeschichte/musikwerkebau/index.html 

This small town has an astonishing history of builders of mechanical
musical instruments, including Michael Welte (yes, M. Welte & Soehne,
Freiburg), Constantin Blessing, et cetera, as You may see at the link
mentioned above. I'm quite sure they can help you with further
information on your instrument.

Regards,

Uwe Gernert from Germany