Window Sill Tiles Removed in Bay Window - Open Cavity

[Mark__s]

We removed the tiles from our window sill and ended up exposing the open cavity.
(1959 Bungalow)

What would be the correct method to close the cavity and replace the tiles with a wooden window sill? I dont think a cavity closer goes smaller enough to fit in to the void.

I was going to:

1. DPC on to the brick , how to fix this in place?
2. No nails ply sheet to close the cavity
3. Wooden window sill on top
Thoughts?

The cavity has a good draft and no sign of moisture in there.

Final and separate question, should I take out the wool(?) from the cavity and replace with Celotex? Anything else I should be doing? Thanks!!

 

[Bargain Bucket]

I'd use a cavity closer. Trim the cavity closer to the size of the cavity.