Hi Ali
for some odd reason I was thinking about typesetting (our grey matter is mysterious stuff)
then I got to thinking about your models and your nail, and how some of the chaps on here
are a whiz with brass.

What if you made/had made a brass bar with a flatted top, of a diameter that took the brass
prongs (plus screw) from some old 13 amp plugs. had these prongs milled to a thickness (or
thickness's of your choice) and then used milled sections of a one size larger tube as spacers
(or washers could do it less elegantly). Length of tool up to you but I'm thinking 100 - 150mm.
So I am thinking that, line - spacing - depth - end shape/s ......... could all be controlled more
finely and repitition would be easy. What do you think then? .......and 'rubbish' is ok too Ali.

Dave