Jim Matthews
Those pre-buyout Marples are dead flat, and nearly featureless.

My Barr framing chisel gets me out of more "interesting" jams and has a belly.

This means I can cut only where I want if there's no squared "land" to register off.
This works like a spokeshave, in reverse.

Curiously, this curve gets me to a tenon of uniform thickness where my flat chisels lead me to taper or make a trapezoid cross section tenon.