the tool used for winding the three flat springs into (they were done three at a time to produce the equal coil spacing) is difficult to find, I have yet to see one on e-bay. I would imagine you would just wind steel rod in the correct diameter through some sort of press. I think I am correct in thinking that the springs are blued in the tool. It can be done but would take a fair bit of trial and error to get the correct thickness/dimensions etc as the old blued hairsprings were made from a different steel than that which we have today. I am sure I have seen in one of my books recently how to make the tool. I will have a look through and see if I can find it.
Paul. I typed all that one fingered while holding the baby