Dear Mr. Rigg,  It is not unusual to find mechanisms of other make
or country inside English cases.  German flute clock makers exported
instruments without casing to many different countries.

On the other hand, German flute mechanisms were not only made in
Germany.  I know of a Mr. Anselmo Gavioli in Modena, Italy, who also
made flute-clocks in German style.  There may have been others.

With kind regards,
Dr. Hans van Oost
Netherlands