So for the knees, I went back to my trusty pile of MDF sheets, cut out the shapes and sanded the top portion so that it tapered on to the lower portion then I glued them together.
The top cap is also MDF rounded off with a power file and lots of sanding. Finally they ware primed and glued on to the rest of the knee pieces. You may have noticed I am a fan of primer, it is because once you prime a piece, you can really see what it looks like.
I then used my old trick of some electrical wire to make the rounded edge around the cap.
Glued to the base board
And that board glued to a bigger base board.
Boxed and primed.
A few casting steps missing, but here are the finished pieces.