Have a photo of the controller without a cover?

No. With certainty: in Rotterdam and Brussels the tram was left untouched and certainly no components were used for the restoration of other trams.
I do know that for example the bronze bell in the tram in Koekelare (school) was stolen: this was told to me by the current owner.
In what state the controller is now: no idea. Theoretically, no one would have looked at it for the last 50 years. One consolation: there are 2 of them and both driver's posts seemed to me to be complete and original.

In Russia, these controllers have not survived, and I just wanted to see its design. :)

A good reason for me to visit next year (summer 2021?) this tram again. Of course: many can happen. I just hope that not too many tram enthusiasts will bother the owner, or worse, to try to enter in his property.