For the header I glued in a roughly square patch to fill in an unwanted rebate on the top RHS.

For the sill I filled in a missing triangular piece on the bottom RHS.

I used glue and a biscuit cutter and biscuits to create a strong bond.

The rest of the day went in to patching any defects in the surfaces using builder's bog.

I am using a brand from "Solvers" which appears to be robust and achieves a good adhesion to the wood.

I have already used this for the installed kitchen window frame and it is lasting well.

During the rest of the week I continued paint stripping on the second frame.

The "safe" paint stripper worked reasonably well but I ended up using a $40 container to strip just the one window.

In the end, despite nine applications to the window sill, I was unable to remove a coating of primer with some Brunswick Green top coat over it.

I had to apply some Methylene Chloride stripper to this to finally work back to the bare wood.

After this I gave is a good wash down with the pressure washer and next I need to do a little bit of sanding to reach the raw wood on all surfaces.