Nathan, thanks. Appreciate the feedback on the drawbore, I was thinking that was how it was accomplished. I would also think that one would have to have a slight taper on the far end from the shoulder to assist in driving the peg in place or use a tapered peg for that matter. I'll have to look it up.
Yrti, thanks. The square hole in the tenon is neat, adds to the joinery and the looks.