I've started with this:
in all its missing buttons and unzipping zipper glory...
And I've turned it into this:
It now has a hood :)
I've taken the whole thing apart and used a 18month spring coat to roughly have a pattern for the back. I've taken out the cowl, the pockets and the zipper, and I have used the cut out bottom to make a hood. So now it looks a lot like the winter coat I bought recently to replace this one.