Of course John I never doubted for one minute that your knowledge was acquired by legitemate means. Sounds like you had a very interesting occupation. Am I to assume you have now retired?
My knowledge of the possible criminal use for an automatic centre punch came from teaching metalwork in the early seventies in a difficult school where one had to be aware of which tools were likely to be attractive to light fingered pupils.
One pupil I recall who I knew to have been in trouble with the police for stealing lead from the local town hall roof, ask me one day if he could make a grappling hook. His request was of course refused.