remove the batten in front of the keyboard by unscrewing the three screws located on the underside of the bottom

if you want to transpose down, remove the left transposition block

take the keyframe and move the keyboard to the left. Since the keyboard is loose in the instrument you will also have to push it a bit inward

put the batten in front of the keyboard back. Don´t forget the three screws, especially when you have to move the instrument later

fill the gap with the transposition block from the bass. Both transposition blocks are identical

with the keyboard in the left position the top jacks have no key to stand on. If you want to transpose up, you have to lift those jacks and put them on the bottom guide (or take them out of the instrument), move the keyboard and put the jacks back. The same procedure with the bottom jacks when you transpose down

All my harpsichords have the possibility to transpose.

Italian harpsichords a1: 415Hz (bottom position) - 440Hz (top position) or a1: 440Hz - 466Hz (top position)

Flemish and French harpsichords (including ravalements) a1: 392Hz - 415Hz (middle position) - 440Hz