The Norfolk Knife, or Sheffield Year Knife.
This leaflet was produced 1990, since then the Knife is displayed at the Cutlers Hall, Church Street the home of Company of Cutlers in Hallamshire.
https://cutlers-hallamshire.org.uk
My mother used to say "For two pins" in the sense of "I am very tempted to", as in "If you don't behave, for two pins I'll give you a good hiding". From memory, someone must have provided her with the pins quite often.
Was this a commonly used expression?