Now that's an entirely different diagram to the one I saw in the workshop manual! There is also another spacer/plate involved. Is this from a later model to fix detaching top lamps?

On another note, the housing has detached from the foam. Foam glued nicely with a Sellys flexible Quickfix Polymer Ultra Repair. (10g for about $5)

The double sided tap holding housing to foam has let go.

Now seeing the diagram above, it does make sense that the foam is a cushioning material, but where are the posts and spacer from?

I'll try scraping the double sided tape off and gluing to the foam. This polymer stuff seems pretty good!