The real reason for this post is to praise the English "Pig Sticker". The mark on the chisel is at 60mm and this is the first pass. I'm about 30mm deep or half way to desired depth. It may take two passes to finish the mortice off if I back off a little for fine control as the chisel nears planned depth or I could just go for it as there is plenty of wood between the bottom and the other side. This is without being heavy handed, nice controlled chisel hits so as to keep every thing going where wanted. It doesn't get much better. The pig sticker is a Ray Iles chisel from TFWW , one of the best buys in woodworking.
Here are the legs marked out and drilled for drawboring:
Here is the pig sticker in action: