OK...
So. Release the four fifths of the back leg and set them up in the workmate for finishing.
I thought I'd taken more pictures, but you get the idea.
Because I've changed my mind and I'm now fitting a leg vice, I had to buy some more timber. I got the cutting service in the shop to cut the board into 100mm widths.
Glue up four fifths of the front leg.
Spend an hour sharpening two chisels and a plane iron. Hopefully once I get good at it I'll just need a couple of strokes on the coarse and then fine grit. I don't sharpen enough because I'm rubbish at it, so I always need to do more when I do.
Realise that I've made a mistake. Two of the front leg boards are supposed to have the mortice for the St. Peter's Cross to go into. Spend a few moments cursing and considering forcing them apart. Decide not too, it just makes the mortice slightly harder, for me, not a professional like the rest of you.
Plane the back leg components with the freshly sharpened plane. They're about a mm under 70mm, close to square and parallel but I've only got a single bulb in the middle of the workshop, which must be the next thing on the list.