German, with some English aspects, I would say.
The ends and big buttons and big end screws all look German, and the green gauze mesh inside the fretwork looks typically German. The single reed plate is typical of German manufacture, except for the curved shape.
But the bellows and the action look typically English.
The reeds look to be German Silver, not steel, and I see at least one broken one, which wouldn't be easy to replace.
I'd say that the German action doesn't lend itself to a miniature, so maybe that's why they used an English one.
But the English-looking bellows seem to show an effort to make it look like an English made one.