So, to clean up the chatter marks left by my OWT (op. cit.), I turn to another tool I made a long time ago, this from broken library furniture, which gave me some nice thin oak for the cheeks.
Principally this is to form a shallow mortice such as a hinge recess. The iron is a file, ground 3/4” wide.
The design is by Tage Frid, And was published in “Fine Woodworking”. I’ve had a lot of ideas from the compendium.