Received this morning.

For the description of the module and its installation, the User Manual:
https://www.instruomodular.com/wp-content/uploads/2023/10/ochd-expander-Manual-web.pdf

Also here, including installation details:

'On ne devrait jamais quitter Montauban' (Fernand Naudin).
https://soundcloud.com/petrus-major/tracks