Inlet Manifold part. What is it?

[McMasters]

Hello,
Rover 75 1999 2.5 Inlet manifold part query.

Follow up from a recent request re cleaning inlet manifold. After a suggestion of how to clean the inlet manifold by removing the VIS motors and spraying in cleaner I decided to have a look at my old one that resides in the back shed so as I was familiar with the VIS parts that must be removed to access the chamber.
Well, after removing the rear VIS motor from it, I noticed a small flap or butterfly assembly inside the inlet manifold chamber. On closer inspection I noticed it was slightly crooked and loose. Then I saw that this whole small assembly containing it could be slid out. Upon closer inspection I realized that the small shaft still in the back of the VIS motor belonged to the center part of this mystery object flap shaft and had detached.

When the original inlet manifold was replaced the VIS motor used to just run on long after switch off and the service people said at the time it was a fault in the inlet manifold and the whole thing should be replaced. Costly! Which it was and hence the spare one I was looking at.
What I am now wondering is if this small broken shaft was the culprit that caused the original failure and not the VIS motor. Also, can this part be identified, ordered new (or obtained from a broken unit I guess)??????
What is it and what is its part number???????????????
I have attached a couple of pictures and some labels to help anyone interested in identifying it to see exactly what I am referring to.

There is good working inlet manifold in the car that I still intend to clean and prevent VIS stress etc but I thought this may be a cheap solution if I can obtain this part to have a working spare part in the shed for a rainy day.
Regards
McMasters

[McMasters]

TOO Hard?????

[Lates]

The broken part cannot be bought separately.Best to get a dead plenum donated and borrow the part to make a complete unit for a rainy day.