Thanks to the late great Mini King, John Smidt, I've extracted the following Clubman heater diagram from his excellent Mini Kingdom parts catalogue and modified it by showing the various part numbers of the components (the catalogue lists the part numbers on an adjacent page). Also below is the page of heater part numbers from the Leyland Australia Clubman parts catalogue (PUB1052). Unfortunately Leyland didn't bother to show an exploded parts diagram, just an adjacent blank page.
I note that there are some discrepancies when comparing the two documents. I think this is because there were part supersessions that resulted in a different part number. For example the demister hoses part AYG9382 have a Deleted note in PUB1052 and two entries near the bottom for parts AYG9383 and 84 which seem to be the replacements.
Feel free to comment if you can clarify any of the information. I can update the diagram where necessary.
Attachment:
Clubman Heater Final.jpg
Attachment:
PUB1052 Section RO2 Final.jpg