The German baroque form seems to be a direct development of the 'gothic' form, perhaps with Italian influence, but on the other hand the late dates suggest it might be descended from Italian harps. A common feature is the 'break' in the bass scaling; this may indicate a change to wound strings there, or perhaps more likely a different tone colour in the bass was desired. Buzzing bray pins are very common on these instruments. Some are chromatic with up to three parallel rows of strngs; others are diatonic.
As an alternative to a second parallel rank of chromatic strings, some lower-status German baroque harps were fitted with finger-operated hooks on the neck to fret occasional semitones. The usual name for such an instrument is 'hook harp' and it continued as a folk instrument in South Germany down to the early 20th century. In the later 18th century the hooks were apparently refined, and connected to foot-operated acutating mechanisms, leading to the classical pedal harp.
There are a number of very interesting German baroque harps extant, which I hope to add here as I have the time and information. In the meantime, German harpmaker Claus Hüttel has some info, and photos of his replicas, on his website.