Crb - diamond 800 (gem)

Hey!

I got my hands on an CRB (GEM) Diamond 800. Unfortunate the whole inlay is a total mess,
which can be fixed, but we are missing another iron plate as shown in the image. (Metal plate with colored wires)

Anyone who is familiar with spare-parts for the Diamond 800 (or other versions)

Or maybe has one for sale.

Hope to hear from you!

kind regards from The Netherlands.
Bas