A beautiful piece of machining, possibly the best stamping jig I have ever seen. It has the added advantage that it can be adapted to compensate for kerning if longer stampings are to be done and spaces need to be made to look acceptable.. What would be required is a list of the distances from the right hand of the letter to the right hand of the punch, the exception being 'A' and 'V' if used together. I have done a random measurement of my old ¼" letter punches and got these figures. 'D' = 3.6 mm, 'H' = 2.23 mm, 'I' = 4.63 mm, 'K' = 3.47 mm, 'M' = 2.38 mm, 'O' = 2.71 mm, 'W' (the widest letter) = 1.96 mm.
